The objective of this study was to evaluate the influence of different level of copper amino acids complex on growth performance and serum Cu-Zn SOD activity in piglets. A total of 288 (144 castrated males and 144 females) healthy post-weaned at 23-day-old piglets (Duroc × Landrace × Yorkshire) with an average body weight of (8.79±1.15) kg were randomly divided into 6 groups with 8 replicates in each group, and 6 piglets (3 castrated males and 3 females) per replicate. Control group was fed a basal diet, experimental groups were fed diets supplemented with copper amino acids addition level was 25, 50, 100 and 150 mg/kg Cu or 150 mg/kg Cu from CuSO4 of the control group,respectively. Growth performance, serum biochemical parameters (Cu-Zn SOD activity) and diarrhea incidence were measured in the 2-phase feeding program (1-14 d, 15-42 d). Results showed that: compared with the control diets, 1) Diets supplemented with Av-Cu or CuSO4 did not affect the average daily feed intake (ADFI) of weaned piglets; supplementing the diet with Av-Cu, the average daily gain (ADG) was linearly increased (P < 0.05), and the feed conversion ratio (FCR) was linearly decreased (P < 0.05); 90-100 mg/kg Cu from Av-Cu has the same effects on ADG and FCR compared to150 mg/kg Cu from CuSO4 according to linear analysis. 2) compared with the control diets, supplementing the diet with Av-Cu can decrease diarrhea incidence of piglets during the whole experimental period (P < 0.05). 3) Av-Cu has significant effect on serum Cu-Zn SOD activity on day 14 (P < 0.05). This study showed that, oral administration Av-Cu to weaned piglet has the potential to promote growth performance and antioxidant capacity, and reduce diarrhea incidence.