Abstract: Objective To observed whe ther the pregnan trats fluorosis could influence the capability of learning-memory behavior of puprats.Methods Open-field and Morris tests were conducted after the pregnant rats drinking different concentration of NaF for along time.The learning memory behavior,the varieties of the activity of superoxide dismutase (SOD),and the content of malona ldehyde(MDA)in pup rats' bra in were investigated.Results Compared with the control group,the number of standing for low fluoride group rats increased markedly(P<0.01).The fecal particles of the low and high fluoride group significantly reduced.The ambulation in three minutes for rats of the middle and high fluoride group decreased significantly(P<0.01,P<0.05).Compared with the low-fluoride group,the ambulation in one minute of the middle and high fluoride groups decreased significantly(P<0.01).Compared with the control group,the learning ability of middle and high fluoride groups presented deterioration.The activity of SOD in pup rats' brain in high fluoride groups was lower than that of the control group(P<0.05).There was an increase trend for the content of MDA in pup rats.Conclusion Fluorosis of pregnant rats had significant adverse effects on open-field behavior,the capacity of learning,the activity of SOD,and the content of MDA in pup rats.