Zhangjiagang's 2021 population is now estimated at 683,500. In 1950, the population of Zhangjiagang was 3,112. Zhangjiagang has grown by 27,464 since 2015, which represents a 4.19% annual change. These population estimates and projections come from the latest revision of the UN World Urbanization Prospects. These estimates represent the Urban agglomeration of Zhangjiagang, which typically includes Zhangjiagang's population in addition to adjacent suburban areas.