ALTHOUGH their wide distribution in arid lands and their many uses that include fodder and fuel besides the environmental values of soil stabilization, Acacia species are vulnerable to elimination in Saudi Arabia. In this study, seed morphology and patterns of their coat surface sculpture as revealed by scanning electron microscopy besides both seed proteins and seven isozymes profiles were employed for the discrimination and authentication the vulnerable Saudi Arabian Acacia collected from the western region of the kingdom. The scanning electron microscopic study displayed diversity in shape, dimensions, color, central aerole features and coat topography of seeds among different species to be characteristic for each species. Seed protein and isozyme profiles showed high variability among studied species. The UPGMA phenogram and genetic similarity analysis based on combination of seed morphology, protein, and isozyme patterns confirmed the extensive genetic diversity existed in Acacia species.