This study contributed to an assessment of the dynamics of Aleppo pine (Pinus halepensis Miller) plant communities in the Ouled Yagoub massif in northeastern Algeria, which is located in a semi-arid bioclimatic zone. Sampling was carried out in three study areas, consisting essentially of a mixed pine forest dominated by Aleppo pine with 17 plant species, a Holm oak (Quercus ilex L.) pine forest with 13 species, and a juniper (Juniperus oxycedrus L.) pine forest with ten species. The eight plant species common to these three pinewoods are Q. ilex, J. oxycedrus, Rosmarinus officinalis, Pistacia lentiscus, Globularia alypum, Phillyrea angustifolia, Asparagus albus, and Genista microcephala. Among the dendrometric measurements performed on the four species studied (P. halepensis, Q. ilex, J. oxycedrus, and Juniperus phoenicea), the frequency of abundance and density were based on two site characteristics (altitude and exposure). The results show that the abundance frequency values of the four species in the three pinewoods are often close to each other, which is why Aleppo pine cannot form a pure pinewood type. The average density of the four most dominant species is 489 trees/ha Aleppo pine, 395 trees/ha Holm oak, 229 trees/ha juniper, and 63 trees/ha Phoenician juniper. Two parameters, altitude (1000 and 1521 m) and northern exposure are among the factors influencing the density of Aleppo pine stands.