Abstract: On the basis of the of the analysis of the physiological reaction of rice reproduction to low-temperature,several models were developed in the Northeast China.They were the normal model the calculating of daily cool accumutated temperature,the relational model of the accumulated temperature and daily rice sterile rate,the normal probability distribution of the temperatare-sensitive spikelu amount in the rice reproductive growing period,and the model of the evaluation.The forecast of the sterile rate and loss rate in rice plants by the effect of the lowtemp eratwre on the rice reproduction was made with these models.The sterile rate and the yield-drop can be calculated 25 days earlier than rice mature by using daily maximum temperature,minimum temperature and several parameters.The method suited for every region of Northeast China.