Objective To establish an HPLC method for the determination of Cucurbitacin IIa in the Xuedansu Pian. Methods The contents were determined by HPLC with the use of C18 column， and a mobile phase of acetonitrile- water（40∶60）. The flow rate was 1. 0ml·min-1 and the detective wavelength was 212nm. Results The average content of the Cucurbitacin IIa in the 10 instalments Xuedansu Pian was 104. 61%. Conclusion The method is simple， sensitive and repeatable. It is suitable for the quality control of Xuedansu Pian.