This experiment was conducted to study the effects of dietary copper supplemental level on growth performance, wool performance, serum biochemical indices and copper-containing enzyme activities and visceral organ development of 2- to 4-month-old long hairy rabbits. After cutting lanugo, one hundred and eighty long hairy rabbits were randomly assigned to 6 groups with 30 rabbits in each group, the rabbits were feed separately. Rabbits in the 6 groups were fed experimental diets which supplemented with 0 (control), 10, 20, 40, 80 and 160 mg/kg copper (the form was CuSO₄·5H₂O) based on a basal diet, and the measured values of copper content in the 6 experimental diets were 3.25, 13.13, 23.40, 44.56, 83.58 and 163.87 mg/kg, respectively. The trail lasted for 7 days for adaption, and 53 days for test. The results showed as follows:dietary copper supplemental level had significant effects on average daily gain (ADG) and feed/gain (F/G) (P<0.05), the highest ADG was obtained when the copper supplemental level was 80 mg/kg, and the lowest F/G was obtained when the copper supplemental level was 40 mg/kg. Dietary copper supplemental level had significant effects on lanugo production, fur area and wool diameter of rabbits (P<0.05), the lanugo production was the highest and the fur area was the biggest when the copper supplemental level was 40 mg/kg. Dietary copper supplemental level had significant influence on serum urea nitrogen (UN) content(P<0.05), when the copper supplemental level was 40 mg/kg, the serum UN content was the lowest and it was 7.24 mmol/L, but dietary copper supplemental level had no influences on serum total protein (TP), albumin (ALB), globulin (GLB) and ALB/GLB (A/G) (P>0.05). Dietary copper supplemental level had significant influence on the activities of serum copper-zinc superoxide dismutase (CuZn-SOD) and ceruloplasmin (CP) (P<0.05). The serum CuZn-SOD activity of 40 and 80 mg/kg groups was significantly higher than that of other groups (P<0.05). The serum CP activity of 40 and 80 mg/kg groups was significantly higher than that of control group and 10, 20 mg/kg groups (P<0.05). Dietary copper supplemental level had no significant influence on organ development indices (P>0.05). Considering all results of this experiment, the appropriate copper supplemental levels are 40 to 80 mg/kg (the measured values of copper content in diets are 44.56 to 83.58 mg/kg) for 2- to 4-month-old long hairy rabbits.