2006–2007: Debut with Timeless and commercial success In August 2006, SM announced that Zhang would officially have her broadcast debut with a performance of her debut single "Timeless" featuring Xia Junsu on MBC's
Music Core the next month. Prior to the official release of her single, "
Timeless" was available for free download starting on August 31 in five Asian countries. Her debut single, "Timeless", was released on September 8. It is an R&B song which is a Korean version of the original single by
Kelly Clarkson and
Justin Guarini. The music video was a two-part installment, starring
Lee Yeon-hee and
Super Junior members
Han Geng and
Siwon. The music video ranked No. 1 on Melon's Video Chart for four full weeks. Within ten days of debuting, Zhang entered the "Take 7" chart on
SBS's
Inkigayo. Zhang continued to promote the B-side track from her debut single, "Y (Why...)," in December 2006. SM also released a "Timeless" documentary version of her "Y (Why...)" music video. This music video reveals her hardships during training; it also showed many behind the scenes clips of her promotion of "Timeless", including never-before-seen footage of her with Xiah. However, promotions for "Y (Why...)" ended quickly, and SM announced that she would be on hiatus from the music industry throughout the rest of the year to prepare for her major debut in China in the end of the year. Zhang made a surprising guest appearance at TVXQ's second Asia tour concert in
Seoul,
South Korea on February 23, 2007. She performed "TRI-ANGLE" with TVXQ, singing a part in the song that was previously performed by
BoA. She made a second appearance with TVXQ on November 24, 2007, in
Malaysia for the same concert, and was TVXQ's regular guest star for their "O" Asia tour until its finale in June 2008.
2008: I Will Zhang's first
Mandarin album,
I Will was originally announced to be released in late 2007, but the release date was pushed to early March 2008. The album was finally released in different regions of China starting March 3, 2008, and on March 28, 2008,
I Will made its Asia-wide release. Before the release of the album, two music videos were released on February 27, 2008, to promote the album. Similar to "Timeless", the two music videos "I Will" and "The Left Shore of Happiness", are one story but separated to two parts.
Han Geng,
Siwon, and
Lee Yeon-hee are also the cast for those two music videos. After the album's release, Zhang received praise from various industry professionals.
Golden Melody Award-winning
Taiwanese American singer-songwriter
Leehom Wang complimented Zhang's singing and was surprised to hear such a strong voice coming from only a nineteen-year-old. During a radio broadcast, Hong Kong-based singer-songwriter,
Hins Cheung compared her "soulful" vocals to well-known R&B vocalists such as
Whitney Houston,
Leona Lewis and
Christina Aguilera. He was impressed at the "international-level music" of the release and said he felt there was a lot of "power in this nineteen-year-old." On May 25, 2008, Zhang received her first award, following the release of her Chinese album, at the 5th Annual Music King Global Chinese Ultimate Song Chart Awards for Female Mainland Newcomer with Most Potential. In her speech, she expressed wishes for more financial support towards the
Sichuan earthquake that had devastated her home province two weeks earlier. Throughout the months of May and June, Zhang attended many online interviews and made numerous variety show appearances, as well as a short university tour to raise money for the Sichuan earthquake. A solo fan meeting for Zhang was held on July 5, 2008, in Beijing. Besides performing songs from
I Will, she also covered songs from notable R&B female singers
Whitney Houston and
Christina Aguilera. On September 13, 2008, fans first heard confirmed news of Zhang's repackage album, which would feature the track "Believe in Love", as well as plans for her second Chinese album. Despite this, the repackage album still has not been released and there has been no other announcements of it being sold in the future. While Korea's Mnet/MK Music Festival was being held on the same night, Zhang attended the 6th Annual Southeast Music Ranking on November 15, 2008, winning the award for Best Mainland Newcomer. Her win was followed by numerous invitations to other award shows throughout the month of December, including the 2008
Tencent Star Ceremony, BQ 2008 Celebrity Ranking, and the 1st Annual Mengniu New Music Festival.
2009–2013: Moving On, second album recordings and hiatus The beginning of 2009 saw Zhang's Chinese activities come to an end as she started preparations for her second album. Activities for
Chinese New Year brought her alongside
Super Junior-M to many activities, including her first appearance on China's biggest television broadcaster,
CCTV, for the Dance & Music Spring Festival Gala. She was also in Shanghai on January 9 to film for a song collaboration between many popular Chinese pop artists, such as
Show Lo,
Fish Leong and
BoBo., On February 6, 2009, Zhang flew to Thailand for the second time in her career to attend the Bangkok concert stop in the SMTown Live '08 tour. For that weekend, her activity schedule was tight as she was required to fly throughout Asia for activities. Less than 10 hours after the end of the Bangkok concert, Zhang flew with members of Super Junior-M to
Guangzhou, Guangdong, China to participate in the 8th Annual Future Star Competition, which also featured
JJ Lin,
Eric Tsang and
Dicky Cheung. She returned to South Korea for album preparations on February 9, 2009. On March 7, 2009, Zhang was the opening act for the last Super Show concert in
Chengdu on March 7, 2009, singing "
I Will" and "
The Left Shore of Happiness". Aside from a performance at the Descendants of the Dragon concert hosted by
Jackie Chan, Zhang was relatively inactive as she remained in South Korea to record her second single. Finally, a year and a half after the release of her first album, a teaser for her upcoming song, "
Moving On" was released on October 15. Four days later, the full music video was released through S.M. Entertainment and
Sohu. The music video features Zhang reflecting back on her memories of the fictional relationship between
Donghae (of
Super Junior) and herself before they break up. Despite fans' general disappointment towards the music video being only a slideshow of photos, it was highly anticipated. On October 23, a week before the single's release across China, a joint press conference was held for both Zhang and
Super Junior-M for them to officially announce their new releases to the Chinese media. After three short months of promotions for "Moving On", Zhang announced on her
Cyworld that she would be returning to South Korea on January 24 to prepare for her second Chinese album. Zhang posted on her
Sina Weibo account that her album may be released in September or October. Despite this, the album was eventually delayed. During the summer of 2012, Zhang once again announced on her Weibo account that she is busy recording for her new album and it may be released in September or October. Unfortunately, the album release was once again pushed back. In June 2013, labelmate
Zhou Mi posted on his official Weibo account hinting that a new album from Zhang may be forthcoming: "Good voices with great potential should not be buried; anticipating Liyin's transformation from a pupa to a butterfly! New album, hurry up and release!"
2014: SM The Ballad, Agape, Not Alone On February 3, it was announced that SM The Ballad would make their comeback in the month after more than 3 years of hiatus, and Zhang would join
Shinee's
Jonghyun, Super Junior's
Yesung,
Super Junior-M's
Zhou Mi, TVXQ's
Changmin,
Girls' Generation's
Taeyeon,
Exo's
Chen, and
Krystal from
f(x) in promoting a new
EP called
Breath. The eight members released their second EP on February 13, with Zhang performing the Chinese version of "Breath" with Chen. The Chinese version of "Breath" was promoted on various Chinese and Korean music shows including
Hunan TV's
The Lantern Festival,
Arirang's
Simply K-Pop, and
SBS MTV's
The Show. Through various Korean news sites on May 23, 2014, it was revealed that Zhang would be releasing a new song in the summer. Fellow labelmate,
f(x)'s Victoria, was cast as the lead actress. On June 18, news arrived that Zhang's music video filming was underway. SM confirmed with Korean media outlets that two more labelmates,
EXO member
Tao and actor
Song Jae-rim were added to the cast. Zhang's third digital single
Agape was released August 2, 2014, on
Baidu Music exclusively for the Chinese market, before a wider release on Korean online music stores four days later. Agape was promoted on various Korean TV shows like
Arirang's
Simply K-Pop,
SBS MTV's
The Show and
Mnet's
M! Countdown. Zhang also made an appearance on CCTV Global Chinese Music Chart to promote the song in China. On August 7, Zhang announced during a live Weibo interview that a new single will be released after promotions for
Agape; the song and its music video will be a sequel to "Agape". On September 20, Zhang released her fourth single
Not Alone in China through Baidu and then later released in South Korea through Korean music sites MelOn, Genie, Naver and Bugs on September 22. The single is a remake of
Tiffany's "By Myself" from the SBS drama series
Ja Myung Go. The song is the continuation of the story line of her previous single
Agape. To support the release of her latest single, Zhang had a showcase in Beijing on September 22 with EXO members
Chen and
Tao with
Tasty as special guests. At the showcase, Zhang performed "Agape", "Back Then", "I Will", "Breath", and "Not Alone".
2017–2020: Return to China and new agency On February 28, 2017, on a live Yizhibo broadcast, Zhang revealed that her contract with SM Entertainment will expire in April 2017 and she decided to pursue her career in China. On August 15, Zhang's Weibo profile was updated to indicate that she was now managed by Beijing-based talent agency
Show City Times; however, the company did not officially announce her until December 31, 2018, when a Weibo post was shared with her image attached. While under Show City Times' management, Zhang released three new songs: a duet with singer
Henry Huo called "Lonely"; a soundtrack song called "Answer" for the Chinese TV drama,
The Remedy; and finally, and a song called "Ashes of Time" that was featured in
Tencent Pictures' feature film,
Sword and Fire. Despite these releases, Zhang's time with Show City Times was short-lived. On September 15, 2020, it was announced on Weibo that she had signed with Beijing S.W. Culture Media. In July 2022, It was confirmed through Weibo that Zhang signed with iFlytek Music.
2023–present: Return to Korea On October 26, 2023, Zhang competed on the third season of
JTBC survival battle
Sing Again - Unknown Singer Competition as singer No. 70, its also marks her first appearance on South Korean national television in 15 years. Zhang was later eliminated on the seventh episode. On December 19, 2023, Zhang released digitally her second studio album
The Tide of Life which composed of ten-tracks previously released since 2022 after she signed with iFlytek Music. On December 29, 2023, Zhang made appearance on
Kim Junsu's year-end concert "XIA 2023 CONCERT Chapter 1: Recreation" with performance duet song "Timeless" in 15 years. On February 16, 2024, Zhang released a duet single with ballad singer Lee Jung-bong titled "How Have You Been?", as a remake of Lee Jung-bong's own song and was released in Korean and Chinese version. On June 29, 2024, Zhang and
Super Junior-M's
Zhoumi released a single titled "Don't Go Today" through Easy Entertainment, a remake single of Ben and Lim Sejun's "Don't Go Today" (2016). ==Controversies==