Since the black pine is one of the most common pine species in Turkey, the present study was carried out and the belowground and aboveground biomass developments of natural black pine individuals was modeled because there is no reliable model for estimating especially the belowground biomass for the natural stands. Moreover, the biomass expansion factors (BEF) and biomass conversion and expansion factors (BCEFs) were calculated for the black pine components. In addition, by the diameter groups, the leaf dry matter contents (LDMC) and root/shoot ratios were determined. Totally 34 sample trees were measured in various diameter and height groups in Kizilcahamam Forest Enterprise. The models utilizing DBH (diameter at breast height) and H (tree height) as independent variable yielded stronger relationships than the models, which use DBH as independent variable, did. LDMC values show linear increase from the small diameter groups towards the large diameter groups. BCEF values changed from 0.063 to 0.825. Mean root/shoot ratio was calculated to be 0.137+/-0.016.