In order to detect the DNA damage in digestive glands cells of Ruditapes philippinarum exposed to different concentrations of fenvalerate for 25 days respectively,R.philippinarum were divided into six groups and evaluated with comet assay method.The DNA damage parameters such as the comet rate,the tail length,the percentage of tail DNA,the tail moment and the olive moment were statistically analyzed by Comet Score 1.5.On the basis of one-dimensional regression equation we selected greater influenced fly parameters after comparing with SPSS 16.0 and constructed the multiple-dimensional regression equation.The results showed that DNA damages in digestive glands cells of all exposed groups were observed and the parameters of each exposed group were significantly different from the control group(P<0.01).The DNA damage in digestive glands cells of control group was minimal.The tail rate of control group was 8.06%±1.94%,the percentage of tail DNA,tail moment and olive moment were nearly 0.The value of each parameter of all experimental groups with exposure concentration from 0.067 5 mg/L to 1.080 0 mg/L was significantly increased.Our research indicated that there was a dose-effect relationship between fenvalerate and DNA damage in digestive glands cells,which increased regularly with the exposure concentrations.All DNA damage parameters were highly relevant to the exposure concentrations.The one-dimensional regression equation(P<0.05)and multiple-dimensional regression equation(P<0.02)had significant statistic meaning,which might be an effective way to estimate the exposure concentration and time of fenvalerate.Our research provided new methods and clues to analyze the genotoxicity of aquatic species caused by the pollutant of pyrethroid pesticides in the coastal sea of China,which could be broadly applied.