Abstract: After different samples of chilled loin pork packaged in atmospheres containing CO+CO₂+N₂(CO-MAP), high level O₂+CO₂+N₂, low level O₂+CO₂+N₂ and vacuum-packaging(VP), were stored at (4±1)℃ for three weeks, the microflora counts of the chilled pork were measured every week. The results showed that: 1)In CO-MAP, the growth of spoilage bacteria (Pseudomonas, Brochothrix thermosphactum and enterobacteriaceae, except for Lactic acid bacteria) were inhibited; 2) O₂-MAP is good for aerobic bacteria growth, and the Pseudomonas, Brochothrix thermosphactum and enterobacteriaceae were not apparently inhibited, thus unsuitable for practically large-scale production, it can only be used for short time storage (one week); 3) The dominant bacteria of vacuum packaging and CO-MAP packaged chilled pork are Lactic acid bacteria, but for chilled pork packaged in O₂-MAP, the dominant bacteria are Pseudomonas.