Chilled pork loin packaged in a controlled atmosphere with CO+CO₂+N₂(CO-MAP), high oxygen level O₂+CO₂+N₂, (high O₂-MAP), low oxygen level O₂+CO₂+N₂ (low O₂-MAP) and vacuum-packaging(VP) were stored at (4±1)℃ to study the effect of atmosphere composition on its physicochemical properties and sensory characteristics over a period of three weeks. The results show that: (1) CO-MAP was the best method to extend the shelf life of chilled pork. The metmyoglobin and fat oxidation were delayed and the meat color was bright red; (2) Vacuum packaged (VP) chilled pork had low TVB-N and TBA values, however, it was dark pink in color and had more pork extract loss; (3) Chilled pork packaged in O₂-MAP had high TVB-N and TBA values over 21 days of storage. The meat color turned to brownish after one week of storage. Off-flavor was observed after two weeks. This method may be only suitable for short-term (one week or less) storage.