Rice is a stable food for a many of the countries in Asia and Arica. The climatic conditions favour thecultivation of this crop in Asia and African countries. Rice is grown under the anaerobic condition and it isan important point source of greenhouse gases such as Methane, carbon-di-oxide and nitrous oxide. Bluegreen algae are belonging to cyanobacterial group and application of Blue green algae are emerging trendin rice cultivation which converts the radiant energy into chemical energy and also supplies nitrogen to thecrop. It is an eco-friendly sustainable agricultural practice for production of biomass of very high value andemerged potential as biofertilizer which are economical and environment friendly. Application of this bluegreen algae in agriculture increases the yield of the crop by the addition of nitrogen and also reduce theemission of green house gases in rice cultivation systems.