Most of Changshu residents are of Jiangsu-Zheiang pedigree, speaking Taihu Lake patois of Wu dialect that carries a Shanghai accent. While Han Chinese here comprise the major ethnicity, Changshu also features a number of ethnic groups, including Hui, Manchu, Mongol, Zhuang, Bai, Miao, Gaoshan, Lahu and Buyi, etc. Toward the end of 2012, the registered population was 1, 067, 800 – 615 heads more than the figure reported for the previous year, with 519, 500 being male and 548, 300 female. New born of the year was 8, 053, birth rate being 7.54‰; 8, 648 died in the same, death rate being 8.10‰. The natural population growth rate was -0.56‰. Changshu’s permanent residents in 2012 was 1, 507, 100, with urban residents being 965, 300. Population density was 976 per km2, and the mean lifespan was 81 years. Changshu’s prosperous economic development stands an attraction to migrant workers. Temporary residents toward the end of 2012 mounted to 793, 400. The urbanization rate of the city’s registered population was 72%, 1.5% up from that in 2011.

The total acreage of Changshu is 1, 276.32 km2, with 386.06 km2 being water area. The total plough-able land is 42, 265.01 hectares, of which 27, 450.64 ones are paddy field, 5, 600.40 irrigation field, and 9, 213.97 dry land. The total construction land of Changshu is 38, 111.94 hectares.