Abstract: Objective To study genetoxic effect of reclaimed water in Tianjin.Methods Reverse phase C-18 solidphase extraction(RP-C18SPE)was used for the extraction of target compounds from water samples.Cell cytokinesis block micromuclei test and Ames test were used to detect genetoxic.Results Ames test showed that both untreated reclaimed water and treated reclaimed water could induce mutation of TA 98 and TA 100 strains.But Cell cytokinesis block micronuclei test was negative.Conclusion Ames test showed that after treatment,organic pollutant was not completely removed in recaimed water,which showed mutation effects.