First comprehensive data on the floristic composition of the soil algae in relation to edaphic factors in Wadi Allaqi Biosphere Reserve were recorded during 1996-7. Twenty-four species of soil algae belonging to 15 genera and three divisions viz., Cyanophyta (15 species), Chlorophyta (six species) and Racillariophyta (three species) were isolated and identified. Among them, 13 species; Lyngbya allorgei Microcystis pulverea, Oscillatoria pseudogeminata, Phormidium foveolarum, Phormidium subfuscum, Schizothrix calcicola (Cyanophyta); Bracteacoccus cohaerens, Gloeococcus minutissimus, Keratococcus bicaudatus, Muriella terrstris, Pseudococcomyxa simplex (Chlorophyta); Navicula cincta and Navicula rhyncocephala (Bacillariophyta) were recorded for the first time in the soils of Upper Egypt. Some physico-chemical characteristics of the soil correlated significantly with the number of species and total counts of soil algae. However, no significant correlation were noticed between the soil algae and soil texture.