Abstract: ObjectiveTo investigate the mutagenesis of sodium pentachlotophenol in vitro.MethodsThe mutagenesis of sodium pentachlor ophenol was detected by using Ames test,Mouse Lymphoma Cell Assay(MLA)and chromosome aberration test at different doses.ResultsSodium pentachlorophenol did not induce the reverse mutagenesis of Salmonellaty phimurium TA97、TA98、TA100 and TA102 strain directly or after addition of S₉;High dosage sodium pentachlorophenol could incr eased the mutation frequency of TK gene significantly compared with control group.Sodium pentachloro phenol can induce a significantly increased chromosome aberration rate both with and without adding S₉ mix.ConclusionSodium pentachlo rophenol can induce chromosome aberration of CHO cell,and is a non-genetic or weak-genetic mutagen.