Abstract: In order to extend the shelf-life of beef and keep bright red color in package, the samples of fresh beef haunch muscles were packed under varying modified atmosphere conditions of O₂, CO₂, N₂. The meat samples were analyzed for color difference, microbial changes, weight loss, pH value, total volatile basic nitrogen contrast with the vacancy package. Results show that the modified atmosphere at the level of 45% O₂, 45% CO₂ and 10% N₂ is suitable for chilling beef without decay for 20 days stored at 0～4℃, and the color is well stabilized simulteously.