best places to eat authentic chinese food in Shanghai?

Well....you are in China, so all the food will be authentic Chinese! What you need to determine is what kind of Chinese food do you want and where these places are in relation to where you are staying. Depending on how well and far you've travelled, many of the local 'diner' type places will serve excellent Shanghiese food, plus a bit of Sezchuan and Hunan province foods. I would highly recommend finding your self a good hot pot place. Most are good, and it is hard to find one that serves bad food..