The objective of this study was to analyze the dominant spoilage bacteria of fresh-cut lettuce stored at4 ℃ for 10 days. Based on the surface bacterial species of raw lettuce combined with sensory changes and microbial count and morphology,the possible dominant spoilage bacteria were found preliminarily. In the vitro experiments,10mL broth cultured about 18 h was dissolved in 990 mL physiological salinewith solid-liquid ratio 1∶ 10,in which the processed fresh-cut lettuce were suspended 15 s,and the samples was respectively stored at 4 ℃ for further determination of the dominant spoilage bacteria typically based on physiological and biochemical experiments and molecular identification. The results indicated that Exiguobacterium( M1-1 and P1),Enterobacteriaceae( V4 and M1-4),Bacillus( M3) isolated from the raw lettuce,and Exiguobacterium( M1-1),Acinetobacter( M1-2 and P2),Aeromonas( M1-3),Pantoea( N1 and V3),Enterobacteriaceae( V2) isolated from the fresh-cut lettuce stored at 4℃ were dominant spoilage bacteria. Furthermore,Exiguobacterium( M1-1) was the specific spoilage bacteria. Therefore,it was very important to analyze species and living conditions about the initial bacteria of raw lettuce and dominant spoilage bacteria of fresh-cut lettuce,to control the quality of fresh-cut lettuce and shelf life.