Research on a diesel bus certified to China V emission standards, run China city bus cycle on a heavy chassis dynamometer, the bus was fueled with D100 (the pure diesel), biodiesel blends B5, B10 and B20 (the volume mixing ratio are 5%, 10% and 20% of waste cooking oil based biodiesel blends), to carry out the emission characteristics of Particulate Matters (PM) carbonaceous components. The results show that China five bus's exhaust particulate carbonaceous components include Organic Carbon (OC) and Elemental Carbon (EC), where OC account for 73%~82%, and the main components of OC are OC2 and OC3. Biodiesel has no effect on the OC composition ratio of vehicle exhaust particulate matter; With the increase of biodiesel mixing ratio, the emissions of bus exhaust OC and OC+EC have a decreasing trend, EC emissions have increased, wherease B10 has higher OC emissions; In four particle diameters as PM_0.05-0.1, PM_0.1-0.5, PM_0.5-2.5, PM_2.5-18, OC and EC have the highest emissions in PM_0.1-0.5, EC has almost zero emission in PM_2.5-18, biodiesel can improve OC emission of ultrafine bus exhaust particles (PM_0.05-0.1), which has virtually no effect on the emission of bus exhaust particulate matter; The OC/EC of using biodiesel decreases, especially in PM_0.05-0.1 and PM_0.5-2.5, which weakens the impact on the secondary air aerosol.