Rapeseed meal is used widely in fish feed,but contains a variety of harmful substances,and this restricts its use.So,a 10week feeding experiment was conducted to evaluate the effects of dietary rapeseed meal levels on growth,liver tissue structure and some nonspecific immunity indices of juvenile GIFT tilapia(Oreochromis niloticus)［initial body weight(4.82±0.46) g］.Five isonitrogenous(crude protein 34%)and isoenergetic(total energy 19.2 kJ/g)diets were formulated to contain rapeseed meal 15.0%(control group),30.0%,45.0%,60.0%,75.0% respectively.The results showed that weight gain rate(WGR),specific growth rate(SGR),feed efficiency ratio(FER)and protein efficiency ratio(PER)of GIFT tilapia decreased with increasing the level of rapeseed meal levels,60.0% and 75.0% group were significantly lower than those in control group(P<0.05),30.0% and 45.0% group had no significant differences with the control group(P>0.05).No significant differences in hepatosomatic index(HSI),viscerosomatic index(VSI)and survival rate(SR)were observed among treaments.Proximate composition in whole body of GIFT,crude protein content of 60.0% group was significantly higher than that in the control group(P<0.05),crude fat content of 60.0% group was significantly lower than that in 30.0% group,no significant differences in moisture and ash was observed among treaments(P>0.05).The number of hepatocytes with empty vacuoles degeneration and nuclear migration increased progressively with the increasing the level of rapeseed meal,liver tissue structure damaged increasingly.In serum,alkaline phosphatase(ALP)activity increased with the increasing of the rapeseed meal levels,75.0% group was significantly higher than that in the control group(P<0.05),while superoxide dismutase(SOD)activity declined with the increasing the level of rapeseed meal,60.0% group was lowest,and has significant difference with control group(P<0.05).In this condition,a percentage of no more than 45.0% of dietary rapeseed meal in juvenile GIFT tilapia was advisable.