Abstract: In order to improve the quality characteristics of the Largemouth bass during storage,the Largemouth bass was refrigerated at 4℃ as the control,ultra-high pressure technology (200 MPa,5 min) combined two different composite preservatives (0.15% chitosan+0.50% ε-polylysine,0.15% chitosan+1.5% ε-polylysine) to pretreat Largemouth bass. To evaluate the preservation effects of Largemouth bass during 12 d at 4℃,total bacteria count,physical and chemical indicators (total volatile basic nitrogen,pH,color,shear) were periodically analyzed. The results showed that the shelf life of the controls was 6 d,the shelf life of Largemouth bass pretreated by UHP was 9 d,the shelf life of Largemouth bass by UHP combined with preservatives was 12 d. The shearing force of the ultra-high-pressure group treated by composite preservative was significantly higher than the ultra-high-pressure group and the cold control group alone at 12 d (p<0.05),and the total bacteria count,TVB-N,pH and color of samples pretreated by compound preservatives and UHP which both were significantly lower than those of other two groups (p<0.05). Among them,the preservation effects of the samples dipped in 0.15% chitosan+1.50% ε-polylysine had the best preservation effects,which could suppress the growth of spoilage microorganisms effectively,slowd down the decomposition of protein and maintained the good quality of Largemouth bass effectively.