Abstract: In order to investigate the quality changes of stored paddy and their influencing factors, the quality indexes, such as electrical conductivity rate (ECR), malondialdehyde content (MDAC), fatty acid value (FAV), catalase (CAT), peroxidase (POD) and polyphenoloxidase (PPO) were measured for 180 commercial paddy samples from different storage regions with different storage time periods. Those measured data were analyzed by SPSS10.0. The results showed that ECR, MDAC and FAV of paddy increased with the storage time prolonging and the deterioration enhancing, while the activities of POD, CAT and PPO decreased. Those indexes to some degree reflect the storage quality differences of paddy stored for different years. The remarkable indexes are FAV, ECR, MDAC and the activity of PPO and the most significant index to paddy freshness is FAV. Furthermore, the climate conditions of different storage regions and paddy types have a significant influence on the changes of quality indexes of stored paddy, as well as the freshness of paddy.