was closely monitored to study the diversity of heterocystous cyanobacterium genus Nostoc and their observations were recorded during last three years (July 2020 to June 2023). Cyanobacteria containing soil were collected from the Grassland Biotope and their enrichment cultures were raised, and morphological observations were recorded. All species of Nostoc have been identified upto the species level with the help of available monographs. Total eleven species of Nostoc viz. N. cycadeae, N. paludosum, N. microscopicum, N. shensiense, N. calcicola, N. sphaericum, N. ellipsosporum, N. linckia, N. verrucosum, N. gelatinosum and N. pruniforme have been identified. On the basis of observations, it is concluded that Grassland biotope is one of the most suitable habitats which facilitate the growth of Nostoc species and the fertility of the soil of Grassland biotope is maintained year after year by their occurrence.