In this study we investigated the effects of dietary vitamin E and selenium on the growth and the antioxidant enzyme activities in serum of juvenile tilapia (Oreochromis niloticus). A total of 1500 tilapias with an average initial body weight of (0.37±0.01) g were fed for 70 days with 10 different practical diets according to a 2×5 factorial design: selenium was added into a basal diet at two concentrations (0 and 0.15 mg/kg) to form two types of diets; in each type vitamin E was added at 0, 30, 60, 90 or 120 mg/kg separately to form 5 groups; there were 10 groups in total; there were 3 replicates per group with 50 tilapias; the basal diet without selenium or vitamin E served as the control. The results showed that dietary vitamin E had significant influence on the weight gain, the specific growth rate, feed intake, and the feed conversion ratio (P<0.05). According to the growth performance, the optimal level of vitamin E in the diet could be 63.8670.58 mg/kg. Dietary selenium had no significant influence on the weight gain and the specific growth rate (P>0.05), but the weight gain was higher than the control group when the diet was supplemented with 0.15 mg/kg selenium and 0 mg/kg vitamin E. Dietary vitamin E and selenium had no significant influence on the growth performance (P>0.05). Dietary vitamin E significantly influenced the activities of glutathione peroxidase (GSH-PX) and catalase (CAT) (P<0.05). The activities of total superoxide dismutase (T-SOD) and CAT also appeared to increase along with the elevation of the vitamin E level. Selenium had significant influence on the activities of GSH-PX and T-SOD (P<0.05). When the added vitamin E was between 60 and 90 mg/kg, the groups with 0.15 mg/kg selenium show an increase in the activities of T-SOD, GSH-PX and CAT compared to the groups without selenium. Dietary vitamin E and selenium had significant interactive effect on the activity of GSH-PX (P<0.05). In conclusion vitamin E or selenium alone could improve the growth performance and the anti-oxidation activity in tilapias; the combination of the two may not further enhance the growth performance but could increase the anti-oxidation activity to a greater extent.