Abstract: Objective To explore the effects of maternal sulfamonomethoxine(SMM) exposure during lactating on exploratory and anxiety-related behaviors of offspring mice in puberty.Methods The lactational mice were orally administered with SMM(0,10,50,200 mg/kg) for 21 days.Then the offspring mice were separated by gender and raised normally until postnatal day 49,and their exploratory and anxiety-related behaviors were detected with open-field,black-white alley and elevated shelf plus maze test the next day.Results Compared with the control,the central region time of the male offspring mice with 10 and 50 mg/kg maternal SMM exposure increased significantly(40.6±10.0 and 41.0±11.9 seconds,P <0.05);the standing times in the open-field test for the male offspring mice with 50 mg/kg maternal SMM exposure increased significantly(56.5±8.8 seconds,P <0.01).For the female offspring mice compared to those of the control,the central region time significantly increased(37.3±9.0 seconds) in 10 mg/kg maternal SMM exposure group(P <0.05);the total number of squares crossed in the open-field test significantly increased(159.1±26.0) in 50 mg/kg SMM group(P <0.01);and the total time spent in the black half test was also significantly increased(57.8±8.2 seconds) in 10 mg/kg SMM group(P <0.05). Conclusion The results indicate that maternal SMM exposure during lactation affects exploratory and dysphoric behaviors of the offsprings mice in puberty.