To investigate the effects of conjugated linoleic acid (CLA) on growth and immune indices of large yellow croaker (Pseudosciaena crocea, R), one thousand and six hundred fish with an average initial body weight of (146.25±10.62) g were randomly divided into 4 groups with 2 replicates each and 200 fish in each replicate. Four groups were fed basal diets with 0%, 1%, 2% and 4% CLA, respectively. The experiment lasted for 10 weeks. The results showed that, compared with the control group, the feed efficiency (FE), specific growth rate (SGR), condition factor (CF), hepatosomatic index (HSI) and viscerosomatic index (VSI) were not significantly affected by adding 1%～4% CLA (P>0.05); the activities of lysozyme, IgM and superoxide dismutase (SOD) in serum and SOD in liver were significantly improved by adding 1%～4% CLA (P<0.05), and the activities were increased with the CLA level increasing; the activities of serum complement components (C3, C4) in 2% and 4% groups were significantly increased (P<0.05), the highest activities of serum complement components (C3, C4) were found in 2% group which were significantly higher than that in 1% and 4% groups; the activities of liver SOD in 2% and 4% groups were significantly increased (P<0.05), the highest activities of liver SOD were found in 4% group. No significant difference was found among 1%, 2% and 4% groups (P>0.05). It was concluded that supplementation of 1%～4% CLA in the diet of large yellow croaker could effectively increase the activity of immune indices though it had no effect on growth performance.