Abstract
Sargassumis a common macroalgae found across the world, especially in the warm temperate regions. It is also known as brown seaweed.Sargassumis known for its medicinal and industrial applications. In the present studySargassamsamples were collected from three different coastal regions of Egypt in the Northern coast, Marsa Matrough and Hurghada. In addition to morphological parameters of identification, the collected species were differentiated and further characterized by Inter Simple Sequence Repeat (ISSR), and 18 S rDNA techniques. This led to the identification of four different species, namely Sargassum subrepandum var. rueppellii, S. platycarpum, S. latifolium, S. subrepandum var. massauense from the areas of collection. Four different ISSR primers used enabled differentiation of total polymorphism to the order of 33.24% among them. The phylogenetic relationship resulted in similarity between Sargassum subrepandum var. rueppellii and S. subrepandum var. massauense.