This experiment was conducted to study the effects of chitosan-zinc (CS-Zn) on growth performance, serum hormone and biochemical indices of weanling piglets. One hundred and twenty weanling piglets with an average body weight of 7.25 kg were randomly allocated into 5 groups (3 replicates in each group and 8 piglets per replicate) and fed with basal diet (control), basal diet supplemented with 50 mg/kg Zn as CS-Zn, basal diet supplemented with 100 mg/kg Zn as CS-Zn, basal diet supplemented with 100 mg/kg Zn as ZnSO4 or 3 000 mg/kg Zn as ZnO, respectively. Feeding trial lasted for 35 d. The results showed as follows: 1) compared with the control and 100 mg/kg ZnSO4 groups, diet supplemented with 100 mg/kg Zn as CS-Zn could significantly improve average daily gain (P＜0.05), and significantly decrease the ratio of feed to gain and diarrhea rate (P＜0.05), but there was no significant difference between the 100 mg/kg CS-Zn and 3 000 mg/kg ZnO groups (P>0.05); 2) serum insulin-like growth factor-Ⅰ content in the 100 mg/kg CS-Zn group was significantly higher than that of the control and 100 mg/kg ZnSO4 groups (P＜0.05); 3) compared with the control group, serum alkaline phosphatase activity and albumin content in the 100 mg/kg CS-Zn group were significantly improved (P＜0.05), but serum urea nitrogen content in this group was significantly decreased (P＜0.05). These results indicate that diet supplemented with 100 mg/kg Zn as CS-Zn can improve growth performance and decrease diarrhea rate of weanling piglets, and has similar effects on 3 000 mg/kg Zn as ZnO.［Chinese Journal of Animal Nutrition, 2010，22（5）:1355-1360］