Experiment purpose:To examine the possibility of developing an animal model of Cadmium at cigarette smoking-relevant levels in Wistar Rats and touse this model for studying the effect of Cadmium at cigarette smoking-relevant levels on oxidative injury in rat liver at different stages. We provide the theoretical and experimental date to persuade the people stop smoking and avoid Cadmium intaking.Experiment method:1. ICP-MS assay for the measurement of the content of Cadmium and Zincum in liver.2. The measurement of the content of GSH,MDA and the activity of SOD3. The measurement of the content of ALT,AST in liver.4. To observe the pathological change in liver by H