Objective To explore whether hepatocellular ischemia reperfusion (IR) injury elicites the apoptosis of hepatocytes or ischemic preconditioning (IP) reduces the apoptosis (AP) of hepatocytes due to IR injury in the rat, and the effect of IP on AP regulating genes (bcl 2、Fas) protein expresssion. Methods Wistar rats were randomly divided into sham operation (SO) group, IR group and IP group. The latter two groups were futher divided into 3 subgroups respectively and subjected to 30 minutes of ischemia. IP was achieved by ischemia for 5 minutes, followed by reperfusion for 5 minutes before continuous block of the liver influe. The rats were killed after reperfusion for 1.5, 3 and 4.5 hours respectively, then liver tissues were sampled to examine the apoptosis and bcl 2 and Fas proteins. In SO group the rats were killed 3.5 hours after the operation and the liver tissues were sampled. Results Apotosis index of hepotocytes significantly in creased in IR groups compared with that in IP groups (P0.05). Expression of Fas protein was significantly increased in IR group and IP group than that in SO group (P0.05). Conclusions This study shows that: (1) IR injury may activate the apoptosis of hepatocytes by increasing Fas gene expression. (2) IP may decrease the apoptosis of hepatocytes by increasing bcl 2 gene expression.