Changshu is a county-level city located in the Jiangsu province of China. It falls under the jurisdiction of Suzhou and is situated within the Yangtze River Delta region. To its northeast, the city borders the prefecture-level city of Nantong across the Yangtze River.
The city is characterized by a mild climate and favorable terrain that have supported high levels of agriculture since ancient times. Its name reflects this agricultural heritage; the first character signifies "always" or "often," while the second character means "ripe." This naming convention distinguishes it from its neighbor, Taicang, which translates to "great granary."