World Health Organization recommends that mothers feed infants from breast (full breastfeeding) until at least the age of six months.
In China, however, the rates of full breastfeeding before 6 months are quite low (a little bit more than 20%).
Here is a quote of foreign woman who lived for a while in China about the acceptance of public breastfeeding:
In Beijing, breastfeeding is viewed as a positive thing, and breastfeeding in public is fine.
However, many higher-income women think they can't and breastfeeding education is awful (like saying "I couldn't bf because I didnt make enough milk"- often told to them by a doctor- and quitting early, thus letting their supply decrease so they really couldn't). People from the countryside don't have this issue - they just push through breastfeeding because they have to - so it is sometimes viewed as something rural people do, but rare for city folk. So... it's sometimes viewed with extreme curiosity - especially if you are a westerner.
My redheaded self and blonde baby get questions and thumbs-up all the time when we nurse in public places. (Chinese grannies constantly give me thumbs up for nursing) Never gotten ANY rude comments, but lots of genuine curiosity and many, many people telling me how "lucky" I am that I can breastfeed and giving me their sad story about how they couldn't.