Pakistan’s coastline is very rich in vegetation of marine algae because of the abundance of nutrients and the country's mild climate. There are three main categories in the diversity of algal vegetation. These are Rhodophycota, Phaeophycota, and Chlorophycota, with Phaeophycota predominating. One of the most significant groupings that is utilized worldwide for food, fodder, manure, and medicines is the Phaeophycota. The group of brown seaweeds includes the genus Sargassum. Over the year, it is found in extremely high population conditions near the North Arabian Sea coast of Karachi. Holdfast, lateral branches, leaves, vesicles, receptacles, and their transverse section are the morphological structure that is used to study the genus. Their morphology, anatomy, and reproductive organs are then examined further. The four newly reported species are S. cinctum, S. ilicifolium var. Conduplicatum, S. cinereum var. Berberifolium and S. lanceolatum.