【Objective】Human activities have caused global warming. So it is essential to get to know how warming affects rice yield and contents of nitrogen (N) and phosphorus (P) in rice, which may provide a certain basis for prediction of yield and quality of rice grains in future climate conditions. 【Method】In the present study, rice cultivars of Tairuifeng 5 and Zhendao 16 were planted in pots, which were placed into a growth chamber with controlled temperature, 5℃ higher than the air temperature outside for 7 days, at their tillering stage, booting stage, heading stage, flowering stage and filling stage, separately. Then effects of warming at different growth stages on rice yield and content of N and P in the plant were analysed. 【Result】Results show that warming at different growth stages affected significantly yield compositions of rice, with the warming at the booting stage and heading stage being the highest in the effect. The plants of Tairuifeng 5 and Zhendao 16 treated with warming at the booting stage were the lowest in number of grains, seed setting rate and grain weight. On the whole, warming at different growth stages increased significantly nitrogen content in stem, leaf, husk and grain of Tairuifeng 5 and Zhendao 16 (p<0.05). The effect of warming on P content depended on duration of the warming and rice cultivar. Compared with the control, Tairuifeng 5 treated with warming at the tillering stage, heading stage, flowering stage or filling stage was significantly lower in nitrogen harvest index, while Zhendao 16 treated with warming at the heading stage was. Compared with the control, Tairuifeng 5 treated with warming at the heading stage and filling stage significantly was significantly lower in phosphorus harvest index, while Zhendao 16 treated with warming at the tillering stage and heading stage was. 【Conclusion】All the findings in the present study show that the booting stage and heading stage are the critical periods when warming affects rice yield and uptake of nitrogen and phosphorus.