Abstract: ObjectiveTo study the effects of acetochlor and ethametsulfuron on DNA damage of mice bone marrow cells.MethodsThe comet assay was used to detect the DNA damage induced by acetochlor or ethametsulfuron at different dose in vitro and in vivo.ResultsFor acetochlor at the concentrations of 5,10,and 20 mg/L in vitro,the tail DNA of mice bone marrow cells were 9.64±1.84,23.67±4.5,and 41.37±4.21% ;the tail length were 8.80±2.57,34.90±6.33,and 44.70±7.64 px,and the tail moments were 0.95±0.24,5.76±1.12,and 24.82±3.22 TM,respectively.Compared with the control group,acetochlor could affect tail DNA,tail length and tail moment of mice bone marrow cells significantly (P<0.01)in vitro.For acetochlor at doses of 100,200 and 400 mg/kg·bw in vivo,the tail DNA of mice bone marrow cells were 9.72±3.16,23.51±3.60,and 29.63±4.07%,respectively,and significantly higher than those of the control (P<0.01).The tail length were 7.40±2.67,20.60±3.72,and 24.50±4.32 px,with significant differences from those of the control(P<0.01).The tail moments were 0.93±0.30,7.27±0.71,and 14.46±2.60 TM and higher than those of the control(P<0.01).The ethametsulfuron at different dose did not induce significant DNA damage in vitro and in vivo (P>0.05).ConclusionAcetochlor could cause DNA damage of mice bone marrow cells in vitro and in vivo,while ethametsulfuron could not.