Where can I have my letter of no impediment for marriage translated and certified?

Hi, you should get your documents notarized in your own country and get them authenticated by Chinese embassy or consulate. Then you should go to the translation company appointed by the Civil Affairs Bureau in your fiancée’s area. I don’t know if you have to get them notarized again by Chinese notary. In order to get married with her, she has to bring her Household Registration Book and your passport.