This study was carried out on 16-year old trees of Acacia saligna, Tamarix articulata and Prosopis juliflora cultivated in Siwa Oasis and used for stabilization of moving sand dunes. Measurements of biomass production, wood volume and wood density were estimated from different tree species. These species were planted in different positions over the dune surface (foot, medium and crest positions). The results showed that, the crest position was highly significant than medium and foot positions in total biomass production as 139.0, 96.01 and 59.91 t/ha respectively. Prosopis juliflora was highly significant in biomass production when compared with Acacia saligna and Tamarix articulata 153.7, 75.72 and 65.48 t/ha respectively. Total wood volume in the first season showed that, the crest position was highly significant than medium and foot positions in total wood volume 169.2, 112.3 and 69.22 m³/ha respectively, and in the second season the results were 174.1, 116.2 and 71.62 m³/ha respectively. Prosopis juliflora was highly significant in total wood volume when compared with Acacia saligna and Tamarix articulata 172.5, 103.9 and 74.30 m³/ha respectively in the first season, and in the second season the results were 176.4, 107.1 and 78.35 m³/ha respectively. Wood density of Prosopis juliflora was highly significant followed by Tamarix articulata and Acacia saligna was the lowest 0.84, 0.73 and 0.61 g/cm³ respectively.