Contents and stability to air and heat treatment of Ascorbic acid(AA) and Dehydroascorbic acid(DHA) in different common fruits was systematically studied in this paper. The results indicated that different fruits have different AA and DHA contents. Except Chinese dates, the relationship of AA and DHA in the total VC forms a positive one, that is, the richer AA is, and the higher DHA in total VC. AA content of fruits distinctly increases after crushing, while DHA is opposite. Heating time has remarkable effect on fruit’s AA, while heating temperature has different effect on different fruits. Different fruits’ DHA has various response to heating time and temperature.