Ying Guixin, also known as Ying Kuicheng, was a military and underworld figure in the waning days of the Qing dynasty and the early Republic of China (1912–49). He was a leader in the Shanghai Green Gang, Chief of Intelligence under the political leader Chen Qimei's provisional Shanghai Military Government, Chief Inspector of Jiangsu Province, and later Commander of Sun Yat-sen's Presidential Guard. He was also closely associated with Yuan Shikai's government. Ying Guixin was directly involved in the assassination of Song Jiaoren who had been deemed a threat by various political factions loyal to Yuan Shikai.