Abstract: In the actual storage process of rice, the grain loss resulting from hardening, mildew and insect pest caused by the condensation due to the alternations of seasons occurs frequently.To reduce the grain loss, this experiment was carried out in a cube simulation warehouse, and the higher moisture rice with moisture content of 14.35%±0.48% was put into the cube simulation warehouse.The temperatures of the two hollow wall surfaces in the simulation warehouse were set to 0 ℃ and 40 ℃ respectively, to simulate the environment where the rice was stored during the alternate seasons, so as to study the temperature change and moisture migration characteristics of higher moisture rice, and determine the location and time of dew condensation in rice grains.The Matlab simulation software was used to reproduce the variation law of the temperature field of the grain pile.The experimental results showed that during the storage of the higher moisture rice in the simulation warehouse, there was a temperature difference between the inside and outside of the rice grain pile, the cold and hot micro-air circulation and sloped cold and hot peaks were formed inside the grain pile.Water molecules moved to the low temperature part with the hot air flow, and water gathered in the low temperature part of the simulation bin, which eventually bed to condensation.After the higher moisture rice was stored for 48 hours under the ambient temperature difference of 40 ℃, the dew condensation occurred at the low temperature part of the grain pile, that is, the upper layer of the cold wall of the simulation warehouse(the first layer of D′surface), and the dew condensation temperature of the rice grain heap was 7 ℃.The critical parameters of condensation were different because of different grain types, moisture cotent, temperature difference between inside and outside grain pile.