Address:
No.0/6-6, Yuanhu North Road, Qingxiu District.
Cheongsam only looks good if it suits you. Go to the old peaceful place, but don't go in. There is a shop specializing in cheongsam near the intersection. Not bad. You can go and have a look.
There is an opinion cheongsam shop in front of Hualian Road, Daxue Road, which is not expensive.