A feeding experiment was conducted to investigate the effects of dietary lipid level and compound lipotropic agent on growth performance, body composition and activities of metabolism related enzymes and antioxidant enzymes in hepatopancreas of tilapia. Four practical diets were formulated to contain 3 levels of lipid (4.5%, 6.5% and 8.5%) and a level of compound lipotropic agent (0.1% compound lipotropic agent and 8.5% lipid) on an equal nitrogen basis (CP=30%). Three hundred and sixty hybrid tilapia (Oreochromis niloticus×O. aureus) with an initial body weight of (4.21±0.09) g were randomly divided into 4 groups (with 3 replicates of 20 fish) and each group were fed 1 experimental diet. The experiment lasted for 8 weeks. The results showed as follows: with the dietary lipid level increasing, the specific growth rate (SGR) and protein efficiency ratio (PER) were significantly increased (P<0.05), and the feed conversion ratio (FCR) was significantly decreased (P<0.05); supplemented with 1% compound lipotropic agent in 8.5% lipid diet could significantly increase PER (P<0.05), and significantly decrease the FCR (P<0.05). Fish fed the diet containing 8.5% lipid could significantly increase the hepatopancreas lipid and body lipid contents (P<0.05), but the diet supplemented with 0.1% compound lipotropic agent could significantly decreased the hepatopancreas lipid and body lipid contents (P<0.05). With the dietary lipid level increasing, the activities of glutamyl oxaloacetic transaminase (GOT) and glutamyl pyruvic transaminase (GPT) in hepatopancreas were significantly decreased (P<0.05), and the catalyse (CAT) activity and MDA content were significantly increased (P<0.05); supplemented with compound lipotropic agent in 8.5% lipid diet could significantly increase the activities of GOT and GPT (P<0.05), and significantly decrease the catalyse (CAT) activity and MDA content (P<0.05). The results suggest that increasing dietary lipid level can significantly improve the growth performance of tilapia, but the higher lipid levels can damage the physiological function of liver. The results also suggest that 0.1% compound lipotropic agent supplementation in diet can improve the physiological function of liver and growth of tilapia. Therefore, compound lipotropic agent can be added into the diet of tilapia as a safe and efficacious liver protecting additive. ［Chinese Journal of Animal Nutrition, 2010，22（6）:1585-1591］