According to meteorological observation data during the high temperature season in 2013 and the observation results of microclimate and rice fructification in middleseason rice anthesis, two warming modes of rice community during the high temperature season are concluded: compound warming and radiative warming. Panicle temperature is affected not only by ambient temperature, but also by solar radiation intensity. The higher the rice panicle is, the higher its temperature is, and the temperature of the upper rice panicle is higher than that of its lower part. Through analyzing the synchronous observation data of rice panicle and microclimate in 2013, verified by the observation data in 2008, which are characterized with radiation warming, the time proportion with panicle temperature being ≥35 ℃ in the anthesis period (09:00 to 13:00) for middleseason rice is concluded as a quantitative indicator of the high temperature effect on the percentage of unfilled grains. Even when temperature is <35 ℃, the panicle temperature can also be ≥35 ℃ due to intense solar radiation, which leads to high temperature sterility of rice.