The establishment and interpretation of diameter and height structures are essential for forest management decisions. This study aims to describe the diameter structure and spatial distribution of Pinus halpensis populations in the Chettaba state forest (Constantine, Algeria). The knowledge of these parameters is an essential step for their sustainable management. The diameter at 1.30 m from the ground and the total height of P. halpensis individuals were measured on 6 plots along an altitudinal gradient. The height structure shows that trees in the height classes between 5 and 10m have a very high density, indicating low natural regeneration. The total structure indicates that smaller trees are more abundant than larger trees (17.5<d≤27.5cm). These results contribute to the improvement of knowledge on current condition indicators of natural Pinus halpensis stands that can be used as a basis in the management of Chettaba forest