The analysis of C2-C6 non-methane hydrocarbons (NMHCs) was conducted at remote site in Oki Island, Japan from July 24-August 10, 1998. Lower molecular weight hydrocarbons, C2-C5 alkanes, ethene, acetylene, propene, and isoprene accounted for more than 90% of the total measured hydrocarbons. The study of trajectory analysis revealed that East Asia Pacific Rim Region is significantly contaminated from the anthropogenic emission transported from Asian continent by rapid convective movement of air masses. Air masses originating from Pacific Ocean and crossing over Japanese Island were rich in C3-C5 hydrocarbon. On the contrary, the air masses arriving directly to the site without any prior continental influence were more aged maritime air masses. ¿ 2000 American Geophysical Union