Abstract: Ethylene is one of the important factors affecting the postharvest storage of fruits and vegetables. Fruit and vegetable enterprises generally set up storage environment and use packaging to mitigate the impact of ethylene. The effects of temperature（273 K, 283 K, 293 K, 303 K and 313 K） and relative humidity（20%, 60% and100%） on the diffusion behavior of ethylene in cellulose were simulated by using molecular simulation technology.The diffusion coefficient was calculated by Mean Square Displacement（MSD）. The results showed that temperature and relative humidity had significant effects on the diffusion coefficient of ethylene in cellulose（P＜0.05）. The diffusion coefficient increased as the temperature rose in the range of 273～313 K; the diffusion coefficient was observed increasing when the relative air humidity increased from 20% to 100%.