Deji sub-district is located in the northernmost part of Zhangjiagang, boasting a 12-kilometer coastline along Zhangjiagang Bay. The region is rich in natural resources and enjoys a distinct ecological advantage.
Deji is home to over 250 ammonium fiber enterprises, with its core-spun yarn production accounting for nearly one-third of China's total output, making it renowned as the "hometown of ammonium fiber yarn" and a major hub for core-spun yarn production.
The sub-district covers an administrative area of 35 square kilometers and includes eight villages – Fumin, Xiaomingsha, Beiyin, Chaonan, Xintao, Deji, Yongxing, and Shuangfeng, as well as two communities – Yuanfeng and Defeng.