Aerosol chemical species were measured using an Aerodyne quadrupole aerosol mass spectrometer (Q-AMS) in spring 2010, in Fukuoka. The main species were sulfate and organics. Organic data were analyzed using the Positive Matrix Factorization (PMF) method. Two distinct periods (Period 1 and 2) were selected. Period 1 (from March 19 at 19:50 to March 20 at 10:00) was influenced by trans-boundary air pollution. Low-volatile, oxygenated organic aerosols (LV-OOA) were dominant and the hydrocarbon-like organic aerosols (HOA) fraction was as low as 15%. About one-fourth (26%) of the observation period in Fukuoka was influenced by trans-boundary air pollution. In Period 2 (from March 22 at 00:00 to March 22 at 23:50), both local emissions and trans-boundary air pollutants influenced Fukuoka air quality. The HOA fraction was relatively high, although the LV-OOA fraction was about one-third of OA. The trans-boundary air pollution was analyzed using the oxidation state of organic aerosols (OA), obtained by the PMF method.