In this paper, the variation of genkwanin content before and after mimic vinegar-processing has been analyzed by HPLC. The result has shown that there is no difference between the quantity and quality of genkwanin before and after mimic vinegar-processing. It is clarified that acetic acid is not the main reason for the decrease of genkwanin content in the flower of Daphne genkwa during the process of vinegar-fry.