This experiment has been done to study the combustion and performance analysis of biodiesel and it's blends prepared from waste cooking oil.The world is also presently confronted with the twin crisis of fossil fuel depletion and environmental degradation. Fossil fuels have limited life and the ever increasing cost of these fuels has led to the search of alternative renewable fuels for ensuring energy security and environmental protection. For developing countries fuels of bio-origin can provide a feasible solution to this crisis and can as alternative fuels. With this perspective, considerable attention has been drawn toward the production of biodiesel as a direct substitute or a blending option with fossil fuel to increase its performance efficiency.This research at National Institute of Technology, Agartala, Tripura, India has been done in collaboration with Legion Brothers, Bangalore, India as a part of the B.Tech project