Objective To study effect of Caulilide(±)-1 on apoptosis and cell cycle, and its involved mechanism. Methods The DNA break was examined by DNA ladder. The cell cycle and the expression of apoptosis associated proteins were analysed by flow cytometry western blot respectively. The results were determined by flow cytometry. Results Caulilide(±)-1 could induce the apoptosis of S180 treated-group , which the DNA of the cells presentedlad-der. In LLC treated-group , the expressions of apoptosis associated protein of Bcl-2 displayed significant down-regulation, and the P53 did not show changes; Caulilide(±)-1 had a specific effect on cell division cycle of the LLC exposed to Caulilide(±)-1 for 48h, increased the number of cells in G0/G1 phase. Consults Caulilide(±)-1 can induce apoptosis of S180 and LLC. Its molecular mechanism may relate to modulation of the apoptosis associated proteins expression, and may be attributed to increase the number of cells in phase G0/G1.