In present scenario researchers focusing the alternate sources of petroleum products. Based on this, current research work focused the emission study of its characteristics and potential as a substitute for Diesel fuel in CI engines. Current research biodiesel is produced by base catalyzed transesterification of rice bran oil is known as Rice Bran Oil Methyl Ester (Biofuel). In this research various proportions of Biofuel and Diesel are prepared on volume basis. It is used as fuels in a four stroke single cylinder direct injection Diesel engine to study the performance and emission characteristics of these fuels. Varieties of results obtained, that shows around 50% reduction in smoke, 33% reduction in HC and 38% reduction in CO emissions. In result discussion a different blends of the brake power and BTE are reduced nearly 2 to 3% and 3 to 4% respectively around 5% increase in the SFC. Therefore it is accomplished from the this experimental work that the blends of Biofuel and Diesel fuel can successfully be used in Diesel engines as an alternative fuel without any modification in the engine. It is also environment friendly blended fuel by the various emission standards.