The concentrations of organic carbon (OC) and elemental carbon (EC) aerosols were measured in PM10 samples from the atmospheric background site, Zhuzhang in Yunnan, in August 8, 2004 to February 28, 2005. Mean concentrations of OC and EC were 3.13±0.91, 0.34±0.18μg/m3, respectively. The mean ratio of OC/EC was 11.92. OC accounted for about 90.5% of total carbon (TC), while EC had a few contribution. Volatile organic carbon (VOC) exhibited obvious seasonal variation, OC and EC generally exhibited synchronous...