Abstract: Three sampling sites,Chegongzhuang (downtown), Liangxiang-1 and Liangxiang-2 (suburb), are set up in Beijing. PM2.5 (diameter<2.5 μm,fine) and PM10 (diameter<10 μm, coarse) airborne particulate matter(APM) samples are collected using the same Gent stacked filter unit samplers. The APM samples of both size categories were analyzed for some 40 elements by instrumental neutron activation analysis (INAA). The differences in average mass ratios of PM2.5/PM10 APM from the 3 sampling sites indicate the difference in composition and source of APM from urban and suburb areas. Seasonable variation and special weather conditions variation are found for Liang Xiang samples taken during 2004-3~2004-8. Major pollution elements are preliminarily identified by enrichment factor analysis.