Abstract: Waste cooking oil were used to produce biodiesel by pyrolysis and esterification reaction The results showed that main components in pyrolytic oil was main alkanes and alkenes with the carbon chain between C10 and C18(total content reach 64%), and a small amount of carboxylic acid compounds. Fuel properties of pyrolytic products were great promoted by esterification reaction. The esterificatied product exhibited good performances with acid value 0.29 mg/g, viscosity 2.58 mm2/s, calorific value 44 MJ/kg, pour point -7℃, and cold filter plugging point -3℃. They met national standard biodiesel. The performance of diesel engine when blend 0# diesel oil with waste cooking oil biodiesel was tested. The test showed that power and torque of the blending fuel are basically the same, and exhaust emissions of diesel engine are more green than 0# diesel.