Abstract: Objective To explore the genetic toxicity of Sauropus androgynus on the chromosomal aberration in vitro.Methods Experimental liquid was extracted from Sauropus androgynus,and diluted into different concentrations.CHL and V79 cell lines were used as models and cultured with serial concentrations of Sauropus and rogynus extractions.Slides were prepared and metaphase cells were observed under microscope for chromosomal aberrations.Results Sauropus and rogynus caused great chromatid and chromosomal aberrations in CHL cells(P<0.01).At the concerntration of 50% extraction,the group without S9 showed greater capacity in aberration than that of S9 treated extraction group.In CHL cells,the chromatid aberrations were greater than chromosomal aberrations.In V79 cells,at the concentration of 50% Sauropus and rogynus extraction,S9 treated group showed greater effects of aberration induction than in negative control group(P<0.05).Direct effects of Sauropus and rogynus without S9 could not be seen in V79 cells and the chromatid aberration was more than chromosomal aberration.Conclusion Sauropus and rogynus has certain genetic toxicity of chromosomal aberration induction and its molecular mechanism needs further investigation.