We obtained the detailed compositional information of diesel and gasoline exhaust particles, and discussed the possibility of the classification into each emission source. The intensities of Ca+ and hydrocarbons were relatively high in the TOF-SIMS spectrum of the gasoline exhaust particles. The secondary ions such as NH4+ and Si(CH3)(3)(+) were strongly detected from the diesel exhaust particles. From TOF-SIMS images of each type of exhaust particles, Ca+ of the gasoline exhaust particles and Si(CH3)(3)(+) of diesel exhaust particles were strongly detected from the large particles with diameter of 0.3 mu m. From these results, the exhaust particles collected in the atmosphere near the traffic route can be classified by their origin by using TOF-SIMS information. (c) 2006 Elsevier B.V. All rights reserved.