The changing rules of 2-dodecylcyclobutanone according to different package styles and adding free radical scavenger in irradiated beef during storage were investigated. 2-dodecylcyclobutanone was extracted and separated by silica gel column and analyzed by capillary column gas chromatography-mass spectrometry (GC-MS). The results show that package with preventing from light can induce an appreciable lowering of the concentration of 2-dodecylcyclobutanone formed in irradiated beef, but preventing from oxygen does not have the same effect. The effects of different packaging atmosphere (N,2, vacuum, and air) on the stability of 2-dodecylcyclobutanone are almost similar during storage. The concentration of 2-dodecylcyclobutanone can be decreased significantly by adding free radical scavengers, and it will be weakened, however, as the storage time extended.