This study aimed to explore dietary different supplemental proportion of cassava meal on nutrient apparent digestibility, digestive enzyme activities in intestine and hepatopancreas, and serum non-specific immune indices of tilapia. A total of 540 healthy tilapia with the average body weight of (7.50±0.25) g were selected and randomly divided into 6 group with each group had three replicates and each replicate had 30 fish. The fish in the 6 groups were fed isoenergetic and isonitrogenous experimental diets with the cassava meal supplemental proportions were 0 (control), 4%, 8%, 12%, 16% and 20%, respectively. The trial period was 8 weeks. The results showed as follows:compared with the control group, diets added 4% to 20% cassava meal had no significant effect on apparent digestibility of ether extract and calcium of tilapia (P>0.05); diets added 4% to 16% cassava meal had no significant effect on apparent digestibility of dry matter, crude protein, ash and phosphorus of tilapia (P>0.05); diets added 4% to 12% cassava meal had no significant effect on protease activity in intestine and hepatopancreas of tilapia (P>0.05); less than 20% cassava meal added in diets could improve (P>0.05) or significantly improve (P<0.05) the activities of lipase and amylase in intestine and hepatopancreas of tilapia; when diets cassava meal supplemental proportions were 4% to 12%, serum lysozyme and superoxide dismutase activities were increased, but differences were not significant (P>0.05), and there were no significant effects on other serum non-specific immune indices (P>0.05). According to the results of comprehensive evaluation on the basis of dietary nutrient levels in this trial, diets added 4% to 12% cassava meal do not have bad effects on nutrient apparent digestibility, digestive enzyme activities in intestine and hepatopancreas, and serum non-specific immune indices of tilapia, and can reduce the feed cost.