Fresh fish are susceptible to degradation and oxidation by endogenous enzymes after death， such as degradation of adenosine triphosphate (ATP) and protein denaturation， resulting in reducing quality and flavor characteristics. To delay the degradation of IMP and to preserve the flavor properties of fish， rosmarinic acid (RA) and epicatechin (EC) were used to inhibit ACP activity. The flavor characteristic was investigated mainly by electronic nose and gas chromatography-mass spectrometry (GC-MS) in sea bass. The results showed that nucleotides content and K value in sea bass treated with RA and EC decreased significantly， and the IMP content increased from 0.61 μg/100 g to 1.70 μg/100 g and 1.39 μg/100 g， respectively， when the flavor to bitterness ratio was the highest， and the degradation of IMP started after 2 d， and the degradation rate coefficients were 0.079 and 0.037， respectively， and both RA and EC could effectively retard the degradation of IMP. A total of 25 volatile substances were detected by GC-MS in the pre-storage period， including 3 aldehydes， 4 alcohols， 2 esters， 3 ethers， 9 amines， and 4 acids and other alkanes. In the middle of storage， 39 volatile substances were detected， including 2 aldehydes， 1 ketone， 6 alcohols， 6 esters， 4 ethers， 10 amines， 10 acids， and other alkanes. 44 volatile substances were detected， including 2 aldehydes， 7 alcohols， 3 esters， 3 ethers， 11 amine substances， and 18 acids and other alkanes in the late storage period. The volatile odors of sea bass treated with RA and EC were more significantly different from that of the control. RA and EC could also slowdown the water loss in the muscle of sea bass.