Abstract: To obtain the sensitive index to estimate copper intake in the assessment of its impact on health. METHODS：Comparative study by determining the contents of copper in blood， and liver and ceruloplasmin(CP) activity of the rats treated by copper gluconate at different dosages (0，0.033，0.169，0.829， 4.146，20.73 mg/kg) for 90 days. RESULTS：The content of copper in blood did not change significantly in each group with the increase of copper intake， and no statistical difference compared with normal control group (P > 0.05). Correlation analysis showed that CP activity rose with increasing copper intake and showed a positive logarithmic correlation (R2=0.9845，P < 0.05). The content of copper in the liver showed a linear ascending trend parallel with copper intake (R2=0.989，P < 0.05). CONCLUSION： A good dose-dependent relationship was shown between the level of CP activity and copper intake， and between the content of liver copper and copper in rats. The level of CP activity and the content of liver copper in could reflect the level of copper intake at different dosage groups. Determination of CP activity is easier and the sample can be acquired easily， so is more appropriate to be used to evaluate copper intake in the research with large number samples.

Key words: copper, copper in blood, copper in liver, ceruloplasmin