Abstract: The purpose of this experiment is to study the change rule of flavonoids contents in leaves of Acanthopanax senticosus in different harvest periods, and to develop and utilize Acanthopanax senticosus leaves. Ultraviolet spectrophotometry and UPLC-Q/TOF-MS were used to analyze the total flavonoids contents and the composition of flavonoids in leaves of Acanthopanax senticosus in different harvest periods, and the trend of flavonoids compounds was studied. The content of the total flavonoids in Acanthopanax senticosus leaves was higher at the beginning of May, mid-August and late September respectively, but decreased during the growing season from May to August. 11 flavonoids compounds with obvious increasing trend and 11 flavonoids compounds with obvious decreasing trend were analyzed. And the results showed that the changing trends of flavonoids contents in leaves of Acanthopanax senticosus in different harvest periods were consistent by the two methods.