This study investigates the particle emissions from a diesel vehicle fueled with ultralow sulphur diesel (B0, ULSD) and 5 % biodiesel blend (B5) by a chassis dynamometer test under three driving conditions. Elemental carbon (EC), organic carbon (OC), 30 species of polycyclic aromatic hydrocarbon (PAH) and 10 species of oxygenated PAH (oxy-PAH) were analyzed to quantify the chemical compositions of the collected particulate matter (PM). The emission factors (EFs) of OC were increased with B5 by a range between 39.5 % and 113.7 %, compared with B0. Both fuel blends recorded a trace amount of EC (0.25 mg/kg or less). It was found that the B5 EFs of total PAHs were decreased by a range between 15.2 % and 50.2 % relative to B0. 2- to 3-ring species, the dominant PAHs and oxy-PAHs, were decreased substantially when using B5. However, the results showed that biodiesel blend promoted the emission of 4- and 5-ring oxy-PAHs and 5- to 7-ring PAHs. The application of B5 shifted the composition towards a higher proportion of PAHs with higher molecular weight and more oxy-PAHs. Due to the increased emissions in PAHs with higher toxic equivalent factors (TEFs), the application of B5 resulted in an increase in toxicity expressed in BAPeq range from 11.3 % to 117.0 %.