Abstract: By using the difference forms of the multifactor integral regression model,the temperature,precipitation and sunshine hours in the middle rice growing period were comprehensively analyzed. The yield integrated impact index and the weight of multi-meteorological factors were proposed. The results indicated that the cold weather in the late spring in the second ten days of March and cloudy and rainy weather in the third ten days of July were the most important factors affecting the yields. In the late spring,the cold weather led to poor seeding emergence of seedlings and the reduction of basic seedlings per hill,while the rainy weather in June had an adverse impact on flowering and pollination of middle rice. The yield fluctuation during late spring and June was about 190kg/ha. Ten-days yield integrated impact index of precipitation of during the period of summer drought from late July to early August reached at 160-170kg/ha,when middle rice was in the mid-later period of grain filling. Ten-days yield integrated impact index of precipitation in the second ten days of June and first ten days of July,temperature in the first and second ten days of July was about 130-150kg/ha.

Key words: Multifactor, Multifactor, Regression integral model, Middle rice, Climate Suitability, Chongqing