Where can I buy plus size jeans (men) in Shanghai?

Depends on the owner's requirements for quality

Lesser quality, it is recommended to go to places like the Light Textile Market.

Scattered various stores have oversized jeans.

If you want better quality, it is recommended to go to the kind of foreign trade clothing store. The kind of export to domestic sales

There the quality is better, and the quantity is more concentrated.

Recommended owners of a place I often go: East Sanliqiao Road where there are 2 good!