Objective：To study the role of hepatic glycogen reserve in pretecting the ischemiareperfusion injury of rat liver. Methods：A model of rat liver warm ischemia and reperfusion injury (WIRI) was set up. Rats were divided into 4 groups：(1)Group H, given 25% glucose by tail vein injection(2ml,q6h,iv);(2)group L, food was not supplied (drinking unlimited) 24 hours before warm ischemia; (3)control group (group C), rats took food freely; and (4)sham operation group (group N). After 45 min of ischemia, reperfusion for 1/4h，1/2h and 1h, blood was taken to test for ICGR15and GLT(glucagon loading test). Meanwhile, the levels of enzymes (including AST, ALT, AKP) were observed. Results：(1) Hepatic functional reserve (HFP)： ①ICGR15： groupN<groupＨ<groupＣ<groupＬ(P<0.05 or P<0.01). ②GLT： cAMP level in plasma after GLT and cAMP answering rate (CAR)： group N>groupＨ>group C>groupＬ(P<0.01).There were significant differences of ICGR15, GLT between the periods of reperfusion of 1/2h，1/4h and 1h in group H, C and L (P<0.05 or P<0.01). (2) Enzyme level： There were signlficant differences in the same periods among the four groups (P<0.05 or P<0.01), groupN<groupＨ<groupＣ<group L. No difference was observed between 1/2h and 1/4h enzyme level in the groups(P>0.05). (3)Histopathologic changes in the liver：They were significantly milder in group H than in groups C and L, and the changes in group H were similar to group N. The changes in group L were the most severe. Conclusions：(1)Prophylactic increase of hepatic glycogen storage could counteract the injury of hepatic functional reserve that occurs during warm ischemia and reperfusion. (2)The changes of hepatic functional reserve that occurs during warm ischemia reperfusion can be earlier and more sensitively reflected by ICGR15 and GLT than by the routine enzyme parameters of hepatic function.