Abstract: Controlling tiller angle will influence temperature, relative humidity, CO2 concentration and photosynthetic active radiation of population. Based on the relative rice data in 2006, the effects of controlling tiller angle on population ecological characteristics were analyzed. The results indicate that population temperature of treatments from 07:00 to 19:00 are higher than that of CK in the different growth periods. The relative humidity of CK is higher than that of treatments from tiller peak stage to booting stage in the day, while it is contrary from full heading stage to filling stage. CO2 concentrations of treatments are higher than that of CK at elongation stage and booting stage, and there are no significant differences in other periods. The upper light intensities of treatments in vertical distributions of photosynthetic active radiation are larger than that of CK. The extinction coefficient of population is lower. The better group with higher temperature, lower relative humidity, higher CO2 concentration and better light intensity by controlling tiller angle can be formed, which is the base of rice high yield.