To study the protective effect of collagen polypeptide-chromium chelate (CPCC) in HL 7702 hepatocytes treated by alloxan and the possible mechanism. Cells were divided into control group, alloxan-treated group, CPCC group and alloxan+CPCC group. Cell viability, contents of reactive oxygen species (ROS) and superoxide radical (O2.-) , activities of SOD and GSH-Px and MDA content were analyzed. The protective effect of CPCC in H2O2-treated hepatices was also determined. Results shows that Cell viability was significantly increased by CPCC, while the contents of ROS, O2.- and MDA and the activities of SOD and GSH-Px in alloxan-treated hepatocyte were decreased. CPCC had a protective effect in alloxan-treated HL 7702 hepatocytes, acting as an antioxidant.