Microalgal biomass offers a number of advantages over conventional biomass such as higher productivities, use of non-productive land, reuse and recovery of waste nutrients, use of saline or brackish waters, and reuse of CO2 from power-plant flue-gas. The production of microalgal biomass reduces Greenhouse Gases (GHG) and provides biofuel as a replacement for fossil fuels. They are useful for production of food, health supplements, fodder, biofuel, aquaculture, fine chemicals and various biotechnological applications. The most commonly used marine algal cultures are Botryococcus braunii, Chlorella vulgaris, Chaetoceros muelleri, Dunaliella salina, Nannochloropsis oculata, Arthrospira maxima, Scenedesmus quadricauda. The current review provides details of the microalgal biomass with emphasis on strain selection, cultivation, strain improvement and biotechnological potentials.