Abstract: Objective To study genetic and physiological toicity of Irgansan DP300 in Misgurnus anguillicaudatus.Methods Misgurnus anguillicaudatus was exposed to different concentrations of Irgasan DP300 for different times.The mortality,micronucleus rate of red blood cells,and the activities of glutamic-oxaloacetec transaminase (GOT) and glutamic-pyruvic transaminase (GPT) in the liver of Misgurnus anguillicaudatus were determined.Results The micronucleus rate of red blood cells significantly increased with the increase of Irgansan DP300 concentration.The maximum micronucleus rate was the highest for the concentration of Irgasan Dp300 at 2.765 mg/L.Additionally,the micronucleus rate also increased with the prolongation of exposure time and varied from 0.0206±0.0006% to 0.0443±0.0015 %.However,the activities of GOT and GPT gradually decreased with the prolongation of exposure time with a sensitive period for the concentration of Irgasan DP300 at 1.92 mg/L.Conclusion Irgasan DP300 exhibits significant genotoxicity and physiological toxicity in Misgurnus anguillicaudatus.