Zhongshan Torch Hi-tech Industrial Development Zone also known as Zhongshangang Subdistrict or Zhangjiabian Subdistrict, is a national-level hi-tech industrial development zone in Zhongshan, Guangdong, China. Formerly the three subdistricts: THIDZ, Zhongshangang and Zhangjiabian were three separate subdistricts until they were merged in January 1993. The zone lies in the east of Zhongshan, with an area of 90 km2 (35 sq mi). At the 2020 census, it has a population of 289,518.