Biodiesel is an alternative fuel that can be produced from renewable sources such as vegetable and animal fats. It is available as fuel in diesel engines. Also, biodiesel fuel is a type of environmentally friendly fuel that is non-toxic, not perishable in nature. A single cylinder, four-stroke, air-cooled, direct-injection diesel engine was used in the study. In the engine is used as fuel of diesel fuel and 10%, COME (Canola Oil Methyl Ester) was added to diesel fuel.The piston rings between the engine parts are critical in term of leakage and lubrication. The fuel used affects engine performance and emissions as well as the surface structure of the piston rings. In this study, Antor 3LD510 diesel engine was run with 10% canola oil methyl ester blended fuel and the engine carried out subjected to long term 150 hours’ endurance test. The engine was operated at 1500 rpm and under part load. SEM (Scanning Electron Microscope) and EDX (Energy Dispersive Spectrometry) analysis of the first, second and third piston rings were performed. As a result, after the operation of the engine with both fuels, the Cr element was largely determined on the surface of the first piston ring and the structure was not disturbed. When the second piston ring surface distribution of COME10 fuel compared to diesel fuel is examined, it is seen that besides the wear elements, combustion and fuel chemistry in the engine are more effective on the surface. The surface of the third piston ring was found to be close to each other after the operating of engine.