Zhenjiang lies in the southwest of Jiangsu province. It is situated at the intersection of the Yangtze River and the Grand Canal (the Beijing-Hangzhou Grand Canal), the longest man-made canal in the world. It lies to the east of Nanjing, west of Shanghai and south of Nantong.

It serves as an important transportation hub in the Yangtze River Delta. Zhenjiang Port, one of the 5 major ports in Jiangsu (the other four are Nanjing Port, Suzhou Port, Nantong Port and Lianyungang Port), is an important transfer port for goods from the upper and middle parts of the Yangtze River. It is 90 km away from Nanjing Lukou Airport and 60 km from Changzhou Luosuye Airport. The Beijing-Shanghai Railway, Shanghai-Nanjing Expressway, No. 312 State Highway and No. 104 State Highway go through the city. The Beijing-Shanghai Express Railway, scheduled for construction in 2008, will cut the driving time from Zhenjiang to Shanghai to 1 hour.