Abstract: Based on the data of the interval sowing under the field conditions,the influence of meteorological conditions on the number of grain per spike and setting percentage of rice Xieyou 9308 and Shaonuo119 were studied.The result showed that the temperature was the major meteorological factor that affected the number of grain per spike and setting percentage of rice.From 25 to 21 days before heading period,a opposite quadratic regression could be used to describe the relationship between the number of grain per spike and temperature,while the setting percentage had a quadratic regression with the temperature.The number of grain per spike would increase and the setting percentage would be improved when the air temperature was between 28.5℃ and 32.0℃ during the young panicle differentiation period.

Key words: Rice, Rice, Number of grain per spike, Setting percentage, Spike formation stage, Meteorological condition