Abstract: Tilapia fillets packaged in controlled atmosphere with 100%CO₂(Ⅰ), 70%CO₂/30%N₂(Ⅱ), 50%CO₂/50%N₂(Ⅲ)and 30%CO₂/70%N₂(Ⅳ)were stored respectively at －0.7±0.3 ℃. The shelf-life of tilapia fillets was evaluated by the sensory evaluation as well as key indexes such as drip loss and chromatic aberration, microbial changes, and TVB-N.The results showed that the shelf-life evaluated by sensory evaluation parameter was 19, 22, 17 and 13 d respectively, and the difference was significant(P < 0.05);the shelf-life evaluated by microbial parameter was 26, 25, 20 and 15 d respectively. There was no significant difference between Ⅰand Ⅱ(P>0.05), but compared with Ⅲ and Ⅳ the difference was significant(P < 0.05); the shelf-life evaluated by TVB-N parameter was 25, 23, 18 and 13 d respectively, and the difference was significant(P < 0.05). However, the drip loss of tilapia fillets was positively related to CO₂ concentration. In conclusion, the modified atmosphere at the level of 70%CO₂/30%N₂ was most suitable, which could extend the shelf-life of tilapia fillets effectively as well as keep their good appearance.