Abstract: According to the trial of 7 stand densities, the growing rules and volume yields of poplar plantations with different densities under short rotation intensive cultivation (SRIC) system were summerized. Based on the prices of rural building timber an economic analysis was made for different densities. The best spacing with maximum yield and income was suggested for growing small and medium sized rural building timber. The thinning trial shows that thinning didn't increase volume yield.