Microalgae is a fastly Growing Photosynthesis Organism which contains Lipids, Proteins, and Medicines. It grows fastly by absorbing CO2 from Environment and it also Yields higher Oil yield than other feedstocks. Due to the Lack of Technological advancements in Oil Extraction, biodiesel from Microalgae has become a critical issue but Microalgae has a favorable fatty acid composition for biodiesel conversion. The Positive things in Microalgae except for extraction of Oil has influenced to use Microalgae biomass as an additive with Coconut biodiesel in the present work. The Coconut biodiesel also has higher Cetane number, Oxygen composition, and suitable Density, Kinematic viscosity, to run Direct Injection Compression Ignition Engines. The absorption of heat by Microalgae particles in Coconut biodiesel has influenced to reduce Oxides of Nitrogen emissions. The microexplosion of Microalgae particles in the combustion chamber caused to increase Brake Thermal Efficiency thane neat Coconut Biodiesel.