Abstract： Objective To investigate effects of psychological stress combined with sleep deprivation on levels of supemxide dismutase (SOD),glutathione-superoxide(GSH-PX),T-AOC and malondialdehyde (MDA) in rats.Methods one hundred and five male SD rats were randomly divided into 7 groups,each consisting of 15 rats:the control group,the psychological stress group,the psychological stress control group,the sleep deprivation group,the sleep deprivation controt group,the psychological stress combined with sleep deprivation group and the multi-factor control group.The psychological stress model was developed with the Communication Box.Rats were deprived of sleep with the application of a small modified platform.one point zero ml of serum was taken from all the sacrificed animals to measure SOD.GsH-PX,MDA levels and T-AOC activity.Results Compared with those of the control group,SOD and GSH-PX activity increased (P<0.05), T-AOC activity had a tendency to increase.while MDA concentration showed a tendency to decrease in the psychological stress group.SOD activity of the sleep deprivation group increased (P<0.05),the T-AOC activity had a tendency to increase,while GSH-PX activity and MDA concentration showed a tendency to decrease.SOD activity and MDA level of the psychological stress combined with sleep deprivation group increased(P<0.05),the T-AOC activity showed a tendency to increase,while GSH-PX activity diminished obviously (P<0.05).Compared with the psychological stress and sleep deprivation single-factor groups,TAOC and MDA of the multi-factor group were higher than those of the single-factor group (P<0.05).The activity of GSH-PX showed a tendency to decrease,and the activity of SOD was higher than that of the psychological stress group,but lower than that of the sleep deprivation group.Conclusions Antioxidation in rats improved,following psychological stress,sleep deprivation and psychological stress combined with sleep deprivation,with the antioxidative capacity of the multi-factor group being higher than that of the single-factor group.