Abstract: Taking the timber grown in the Eucalyptus grandis plantation as study object, the variation tendency of the basic density, the air dried density and the oven dried density of the timber in both radial and axial directions, and the correlations among the different density indexes were analyzed. The results showed that the density indexes relatively remained stable in the radial direction, and the densities of the timber close to the pith part were relatively smaller. The densities in the axial direction were decreased with the increment of the trunk height between 0-6 m above the ground. The analysis of variation coefficient showed that the timber densities changed less along with the height increase in the axial direction. There were significant linear correlations among the basic density, the air dried density and the oven dried density of the timber, the formulated function might well reflect the correlations of the densities, and the relevant models were reliable.