Abstract: Objective To explore effects of different diet composition on uncoupling proteins 2(UCP2)gene expression of rat white adipose tissue.Methods Male Wistar rats were fed with different diets(including basic diet,high protein,high fat,high calorie 1 and 2 diet)for 2 months.The effects of the different diets on weight and the ratio of fat to body weight were observed.Reverse transcript ion-polymerase chain reaction(RT-PCR)technique was used to measure the expression of UCP2 mRNA of rat white adipose tissue(WAT).Results Body weight and the ratio of fat to body weight in high calorie 1 and diet groups are obviously higher than that in groups of basic diet,high protein,high fat diet(P<0.05),but there was no significant difference among the last three groups(P>0.05).UCP2 gene expression increased in high calorie diet 1 group and high calorie diet 2 group,and no significant difference in basic diet,high protein and high fat group with equal ener gy was observed.Conclusion Energy can induce UCP2 mRNA ex pression of rat WAT,and expression level was related to the energy storing in body.