Corn is abundant in carbohydrate, protein, carbohydrates and other nutrients. However, because of its large embryo, it is easy to be infected by microorganisms and insects, which leads to the deterioration of corn quality. Therefore, the quality preservation and storage of corn is a challenge. So it is necessary to clarify the rule and change of corn storage quality. Corns with initial water content of 13.04%, 14.03% and 14.99% were taken as reasearch objects in this paper. During storage between 70% relative humidity and 20 ℃ (quasi-low temperature environment) , the changes laws of quality indexes such as bulk density, fatty acid value, germination rate, mold activity and microstructure of corn grain were studied emphatically. Otherwise changes of storage quality of corn at 70% relative humidity and 25 ℃ (room temperature environment) were compared. Therefore it can provide reference for safe storage of high-quality corn. The results demonstrated that the germination rate, fatty acid value and bulk density of corn under 20 ℃ were slower than those under 25 ℃. And they were in the suitable storage range in accordance with the national standard. The number of fungal spores increased sharply with the prolonged storage time. Meanwhile it showed significant correlation with the initial moisture content of corn. In other words, the number of fungal spores for corn under 14.99%w.b was stored for 120 d, and the safe storage periods of corn under 13.04%w.b, 14.03%w.b and 14.99%w.b were 180 d, 180 d and 100 d, respectively. The microstructure of corn kernel changed gradually during storage. It means the appearance changed from smooth and tidy to concave and convex folds. Furthermore, the arrangement of starch granules changed from tight structure to sparse and disordered structure. The main factors of corn quality and microstructure change were corn initial water content and storage time, during storage at quasi-low temperature environment. So the change laws of corn storage quality with different water content were explored, so as to provide new research perspective for maize post-harvest to reduce loss and guarantee qualtiy.