Abstract: The paper determined the effects of dietary supplementation with low levels of copper-glycine instead of copper sulfate on growth performance, serum biochemical parameters, and fecal copper excretion in weaned piglets. The results showed that, compared with 200 mg/kg copper sulfate group, the average daily gain, average daily feed intake, gain: feed ratio, and diarrhea rate showed no significant differences in 100 mg/kg copper-glycine group. Compared with the other two groups, the ADG in 50 mg/kg copper-glycine group was significantly decreased and G/F ratio significantly increased respectively. Among the three treatment groups, the serum mineral contents, such as copper and iron had no significant difference. The serum activity of glutamic-oxalacetic transaminase in 100 mg/kg copper-glycine group was significantly higher than that in the other two treatment groups. The fecal copper concentrations in 50 mg/kg and 100 mg/kg copperglycine group were significantly lower than that in 200 mg/kg copper sulfate group. The fecal contents of iron and zinc showed no significant differences among the three groups. In conclusion, these results suggested that dietary supplementation with 100 mg/kg Cu as glycine copper could effectively replace the 200 mg/kg Cu as cupric sulfate, then reduce the additive amount of copper in feed and decrease the pollution of fecal copper discharged to the environment.