In India, Mahua trees are tropical tree, generally found in the northern and central forests. Due to large amount of carbon emission from natural diesel into the environment, it causes to pollution and climate change that could affect health of livelihood. Therefore, it has to shift to some alternate fuel in place of natural diesel that can reduce carbon and pollution emission to the environment. That’s why we opted to blend natural diesel with Mahua oils. Since Mahua trees are cultivated in humid and warm region and it is producing 30 to 200 kg of seeds yearly per tree depending on its maturity. Therefore, it is cheap and easy availability of Mahua seeds can provide a raw material for blending of diesel fuels. The reduction of thermal efficiency by Mahua mixed biodiesel has major challenge. The natural diesel blended with the proportion of starting increasing from (5 to 20 %) of Mahua seeds oil and starting reduction from (95 to 80 %) of natural diesel oil. The diesel engine were operated on the basis of different Mahua seeds oil quantity with natural diesel, and it observed the highest thermal efficiency of blended biodiesel were at (20 %:80 %) of Mahua seeds oil and natural diesel oil respectively. The aim of this experimental is to utilize of Mahua seeds and to check performance and emission characteristics of Mahua blended biodiesel. Further emissions like CO, NOx, un-burnt hydrocarbon, smokes etc. are analyzed with using diesel engine cylinder.