The present study on biological diversity of marine phytoplankton along coastal waters at Veraval was conducted along Saurashtra coast. Water samples were collected at fortnightly intervals from two locations. Three sites each at 20 m intervals were identified for the sample collection at both the locations. Fifty liter each of sea water was filtered through sieve units from all the six sites for collecting phytoplankton. The five classes of marine phytoplankton identified were Bacillariophyceae, Dianophyceae, Cyanophyceae, Chlorophyceae and Chrysophyceae. Total 158 species of marine phytoplankton were collected; nine of them could not be identified. Diatoms were the most dominant group (129 spp.) followed by dianoflagellates (11 spp.), blue-green algae, brown or orange chromatophores and green algae.