Roadside airborne Particulate Matter (PM) with the size smaller than 10 micron (PM10) was collected from four sites in central Phitsanulok, the lower part of Northern Thailand with population of one hundred thousand. Daily samples were taken since June 2003 to January 2004. It was found that the PM10 concentration in the dry season has exceeded Thailand's national ambient air quality standard of 120 mu g/m(3). All filters were analyzed such as element carbon and organic carbon using CHNS/O analyzer and analyzed 12 elements (Na, Al, Si, S, K, Ca, Ti, V, Cr, Fe, Zn, Pb) using Inductively Couple Plasma-Atomic Emission spectrometry (ICP-AES). From the results, it showed that the roadside samples primarily contained the TC, OC, EC and Ca with mean values of 71.61 mu g/m(3), 29.33 mu g/m(3) 42.28 mu g/m(3), and 9.57 mu g/m(3), respectively. The major elements were Si, Al, Fe, K and S.