Abstract: The experiment was conducted with the objective of examining the effects of dietary copper of different forms and dosages on hydrogen peroxide (H2O2) generation of mitochondria from broiler hepatocyte. Copper sulfate and copper methionine have been used as the copper source, and four concentration copper groups were set for each copper source. 288 broilers (Cobb 500, Gallus domesticus) aged 1 day were randomly divided into 8 groups with 36 each and fed with diets as follows: Controls (Cu 11 mg·kg1, group Ⅰ), and high copper (Cu 110 mg·kg1, group Ⅱ; Cu 220 mg·kg1, high copper group Ⅲ; Cu 330 mg·kg1, high copper group Ⅳ) for 60 days under normal condition, three samplecollections were processed at 12dayold, 36dayold and 60dayold respectively to investigate the changes of H2O2 generation of mitochondria from broiler hepatocyte. In result, compared with those of control group, H2O2 generation of mitochondria in high copper group Ⅱ, Ⅲ and Ⅳ of two copper sources were increased (P<0.05 or P<0.01); At the experimental time of the 36th and 60th day, H2O2 generation of mitochondria from broiler hepatocyte in each group of copper methionine were increased compared to those of each group of copper sulfate (P<0.05 or P<0.01). The location of H2O2 generation of mitochondria from broiler fed with high dietary copper were mainly concentrated in mitochondrial complex Ⅳ. The results obtained above indicated that high dietary copper could induce oxidized stress damage in liver; at the same level of dietary copper supplement, the organic copper will lead to much faster H2O2 generation velocity of mitochondria from broiler hepatocyte than inorganic copper. The results can also suggest that mitochondrial complex Ⅳ might be one of attack target spots under high dietary copper stimulation of organism.