The storage process of control temperature by air conditioner in the warehouse was researched aimed at the problems such as the high temperature inside warehouse, the upper grain temperature rising quickly and grain quality becoming stale rapidly during the paddy storage in summer in north area. The changes of temperature, moisture content and quality indexes of the top layer paddy were analyzed. The result showed that the moisture content, germination rate and tasting score of the top layer paddy reduced gradually with the increase of storage time, compared experimental warehouse with control warehouse, which showed negatively liner correlated with storage time; while the fatty acid value increased gradually and positively liner correlated with storage time; amylose and storage time showed the trend of ascended at first and then declined. The change ranges of quality targets in the test warehouse were obviously less than those in the control warehouse during the storage period. When stored for nineteenth months, the quality of the grain in the test warehouse was better than that in the control warehouse; The upper grain temperature was kept below 20 ℃without pest, and moisture content loss in the grain was decreased and deterioration of grain quality was delayed. The safe storage of paddy at quasi low temperature was realized, which have obviously economical and social benefits.