Abstract: The weanling KM mice were randomly devided into three groups：group A as control fed with normal diet；group B fed with 80% energy intake of that in group A；group C 65% enegy intake of that in group A.The intake of protein，lipids, vitamins and mineral elements was the same in the three groups. The dietary restriction （DR） was maintained for 3 and 6 months respectively. The results showed：① DR for three months had no significant effect on blood lactate before and after swimming，while in 6 months DR,both 80% and 65% energy intake help cleaning blood lactic acid after swimming. 65% energy intake could decrease the blood lactic acid before swimming （P＜0. 05），and made the change of blood lactic acid with the time at a lower rate than that of group A. These results indicate that DR for longer time can retard the appearance of fatigue and accelerate recovery.② The survivial time of the mice in anoxia condition was significantly different among the three groups,but it seemed to be caused mainly by the difference in body weight.③ 80% energy intake made no significant influence on the ability of resisting against low tempera-ture,65% energy intake for three months could decrease this ability,but after six-month DR the ability was improved.