In this algal diversity study total 111 algal taxa were recorded from the Purna river basin from class chlorophyceae, cyanophyceae and bacillariophycea. In the class bacillariophyceae total 25 algal taxa were recoded with 15 genus, in class chlorophyceae 36 algal taxa with 15 genus, in cyanophyceae 50 algal taxa with 22 genus from respective seven sites. From the class cyanophyceae 50 species belongs from the 5 orders, 9 families, in class chlorophyceae 36 species belongs from the 9 orders, 10 families. In Bacillariophyceae 25 species were distributed in 15 genus, 13 family and 9 orders. In this research study the most dominant genera was recoded from class chlorophyceae i.e. Spirogyra with 10 numbers of species followed by Cosmarium with 5, Pediastrum with 4, Nitella, Chara, Rhizoclonium with 2 specimens and Staurastrum subsaltans, Trachelomonas volvocina, Schroederia Judayi, Bulbochaete hiloensis, Cladophora, Chlorella sp., Hydrodicton with one genus with one species, from cyanophyceae Oscillatoria genus shows that rich algal diversity followed by Microcystis with 4, Aphanocapsa 4, Spirulina with 3, Lyngbya with 5, Nostoc with 4, Chroococcus with 4, Phormidium with 2 and rest.