By using sampling method of subcompartment that is sampling Probability Proportional to Size(PPS), the volume of subcompartment had been estimated. In order to raise the precision of estimation, the auxiliary factor of the sampling subcompartment must be selected, which related closer to the sampling volume. In other hand the auxiliary factor was required to be measured easily and best to be as basic factor of subcompartment such as the subcompartment volume and the forest crown coverage in the earlier term etc. In this paper the multiplication of sub compartment area with the percentage of forest crown coverage were used as the auxiliary factor of sampling subcompartment. It also was be explained as the area of the trees crown coverage in subcompartment.The results showed that the estimation of volume was 3785580m3 in the year of 2000, and 4162119m3 in the year of 2005. The estimated precision was 69％ and 78％ respectively, only 32 sampling units had been used. The estimation of volume growth was 530020m3. Added it with the volume in the year of 2000, another estimation of volume was 4315600m3 in the year of 2005, witch was among the estimated range (3786341, 4537897) in the year of 2005.