Abstract: The spacing trial with 5 treatments ( 1 ) 2 222 tree ·hm-2 , ( 2 ) 1 667 tree ·hm-2 , ( 3 ) 1 250 tree ·hm-2 , (4) 883 tree·hm-2 and (5) 667 tree·hm-2was established at Guangxi Dongmen Forest Farm in 1993, thegrowth data were collected up to 12 years old and calculated CA I, MA I, Volume with different top diameter, NPVand IRR. The results showed that the volume growth of 5 spacings were high significant up to 6. 3 yrs, not significant from 8. 3 yrs. The age of quantitative maturity of spacing 2 222 tree·hm-2 , 1 667 tree·hm-2 and 1 250 tree·hm-2 was 6 yrs, 6. 5 yrs for spacing 883 tree·hm-2 and 7 yrs for spacing 667 tree·hm-2. The denser the initial spacingwas, the more the amount of small diameter timber and the less the big diameter timber. The harvest rotations of spacing 2 222 tree·hm-2 , 1 667 tree·hm-2 , 1 250 tree·hm-2 , 883 tree·hm-2 and 667 tree·hm-2were 6 yrs, 7 yrs, 7 yrs, 7 yrs and 8 yrs respectively, the NPV were 17 661、18 457、22 257、24 755 and 24 007 RMB·hm-2 respectively and IRR were 56%, 50%, 55% , 58% and 51% respectively. Spacing 883 tree·hm-2 had themost NPV and IRR among the 5 spacing treatments, the rest in the order from high to low were 667 tree·hm-2 ,1 250 tree·hm-2 , 1 667 tree·hm-2 and 2 222 tree·hm-2.