Icariin in "Tangzhi Shuangjiang Cha" was quantitatively determined by HPLC with ODS column, a mixture of MeOH-H2O(60:40, V/V) as mobile phase and UV detection at 270 nm. There was a good linear relationship within the range of 0.1 g/L-0.5 g/L(r = 0.9993). The average recovery was 101.4%, RSD was below 2.7%(n = 3). The method is rapid, simple, accurate and reproducible. And the method is proposed to be used for quality control of "Tangzhi Shuangjiang Cha".