ChanSu, also called toad venom, is originated from the skin secretions of Bufo bufo gargarizans Cantor and B.melsanostictus Schneider.Resibufogenin (RBG) was a major bufadienolide with the content of 1-6% in Chansu [1].And it had strong cytotoxic activities against human myeloid leukemia with IC50 values of 1-10 nmol L-1 [2].However, as a cardioaetive steroid with α-pyrone ring, RBG can adversely affect the myoeardium to produce the most life-threatening toxicity [3].