Hi Sandy,
try Huaihai Rd (crossroad Cengdu Rd) and walk in west direction. Here you should find many wedding wholesalers.
You could also go to the South Bund Fabric Market (direction explained in above conversation).

Hi ! Thank you very much for your reply. have you heard of 七浦录? some people say find gowns there very cheap, is it true? is it a wholesale place?

thank you !

Hi Sandy, sorry but I can not read Chinese (I am actually German living in China). So I dont know which place you mean. Maybe someone else can help???

You seem to be talking about Qipu Road, though you have the character for green rather than road. The first two characters are definitely qipu and that can only mean Qipu Road. It is a place to find all manner of fake goods, but typically all of low quality. I would steer clear of this place for a wedding gown!