Fossil fuels cause the greenhouse effect by emitting CO2 and an estimoted amount of oil deposits are limited. Therefore, people have been interested in alternotive energies. Vegetable oil which is one of the alternotive energies is also eco-friendly renewable energy source and has similar properties like diesel with high efficiency. Also, vegetable oil has been recognized as a method to solve the greenhouse effect caused by CO2 release. In this study, impurities and sediments from WVO(waste vegetoble oil) were removed by separotion step using 15μm sieve. Blending wos performed in HOMO-MIXER by 5000 rpm ot 10 min of mixing time. We mesured viscosities and Iodine values in different compositions of WVO and diesel blends. Finally, we could find out blended oils have enough possibility to use in the diesel car.