Abstract: Objective To explore the effect of cold exposure on the energy metabolism of the organism by observing the changes of anus temperature,blood sugar and lactic acid in the serum of rats.Methods 90 healthy male Wistar rats were randomly divided into eleven groups,one of which was control group with ten rats and the others were exposed to cold with eight rats for each one.The first three groups were exposed to cold condition at the temperature of -30℃ over a period of 30,60 and 80 min.The other six groups were exposed to the same cold condition for 80 min and then rewarmed for 4,8,12,16,24,72 and 120 hour.To observe the changes of the level of anus temperature,blood sugar and lactic acid in serum.Results The levels of anus temperature of the first three groups fell down,showing significant differerence(P<0.01).The levels of anus temperature of the groups which were rewarmed for 8,12 and 16 hours were higher than that before exposure.The difference was significant.The levels of blood sugar of the 30 min ute-exposed groups and 4-hour rewarmed groups were lower than that of the control,while the levels of blood sugar of the 8-hour rewared groups were higher than that of the control.The results showed significant difference(P<0.05 and P<0.01).The levels of lactic acid in serum of the 30 min,60 min exposed groups and 8-hour 12-hour rewarmed groups were all higher than that of the control,showing significant difference(P<0.05).Conclusion The cold exposure had effects on the energy metabolism of rats which were shown by the change in the anus temperature and blood sugar and the increase of the lactic acid in serum of rats.