Objective:To study on the anti-tumor activity of extract and components from Periploca forrestii.Method:The growth-inhibitory effect of extract and components from P.forrestii on tumor cell lines were examined by using MTT assay.Compounds were isolated from the P.forrestii by chromatographic techniques and were identified on the basis of physico-chemical properties and spectral data.Result:Ethyl acetate extract from P.forrestii has strong inhibitory effects against proliferation of K562 tumor cells with the maximum inhibitory of 80.71% at 25 mg·L-1.The component Ⅵ and component Ⅸ has inhibitory effects against proliferation of K562 tumor cells with the maximum inhibitory of 97.48% and 40.56% at 10 mg·L-1.Conclusion:Cell growth in vitro was inhibited significantly by ethyl acetate extract from P.forrestii.Two components have good anti-tumor activity.