Jiangnan is a geographic region of East China, not a city. The name refers to the lands immediately south of the lower reaches of the Yangtze River, including the southern part of the river's delta. It is a cultural and historical region rather than a single administrative unit.
The area encompasses Shanghai, southeastern Jiangsu, southeastern Anhui, a small part of northeastern Jiangxi, and Zhejiang Province. Among its most important cities are Ningbo, Anqing, Changzhou, Hangzhou, Shaoxing, Suzhou, Wuxi, and Wenzhou.
No city named Jiangnan is documented in the Fujian region in the available source material, and no notable characteristics specific to such a place can be stated. The only well-established usage of the term is for the East China region described above.