2009年7月和2010年1月在上海市华东理工大学采样点采集PM2.5样品,应用热/光碳分析仪对样品中的有机碳(OC)和元素碳(EC)进行了测定,并计算得到了二次有机碳(SOC)、char-EC和soot-EC的质量浓度。结果显示:采样期间PM2.5、OC、EC、SOC、char-EC、soot-EC夏季平均浓度分别为(58.87±20.04)、(11.37±4.12)、(3.68±1.27)、(4.37±2.86)、(3.00±1.24)和(0.68±0.30)μg/m3;冬季平均浓度分别为(142.31±45.47)、(16.01±4.43)、(5.53±2.36)、(5.67±2.92)、(5.11±2.35)和(0.42±0.17)μg/m3,除soot-EC外,均呈现夏季低、冬季高的特点。在不同空气质量下,OC、EC和char-EC的质量浓度具有明显差异,且三者均与能见度、平均风速呈显著负相关。夏冬两季soot-EC、char-EC、SOC和POC占TC的百分含量相差不大,其中POC/TC值最高,soot-EC/TC值最低。夏季SOC/TC的比值高于冬季,可能由于气温高有利于发生光化学反应。对8个碳组分进行主成分分析,结果显示,燃煤、生物质燃烧、汽油和柴油车排放对PM2.5中碳组分的贡献显著,并且可能受燃煤和汽油车排放的影响最大。Ambient PM2.5samples were collected in July 2009 and January 2010 at the site of East China University of Science and Technology in Shanghai. The concentrations of organic carbon(OC)and elemental carbon(EC)in PM2.5samples were detected by thermal/optical carbon analyzer. The concentrations of secondary organic carbon(SOC),char-EC and soot-EC were also calculated. Results indicated that average mass concentrations of PM2.5,OC,EC,SOC,char-EC and soot-EC in summer were(58.87 ±20.04),(11.37 ±4.12),(3.68 ±1.27),(4.37 ±2.86),(3.00 ±1.24) and(0.68 ±0.30) μg/m3 respectively,while average mass concentrations of these components in winter were(142.31 ±45.47),(16.01 ±4.43),(5.53±2.36),(5.67±2.92),(5.11±2.35)and(0.42±0.17)μg/m3 respectively. The concentrations of the above components except soot-EC were lower in summer and higher in winter. Under different air quality,mass concentrations of OC,EC and char-EC were obviously different,and they showed negative correlation with visibility and wind speed. The percentage of soot-EC,char-EC,SOC and POC in TC did not show significant difference between summer and winter,with POC/TC ratio as the highest and soot-EC/TC ratio as the lowest. SOC/TC ratio was higher in summer but lower in winter,due to high temperature which probably promote photochemical reaction. Principal component analysis on 8 carbon actions showed that coal combustion,biomass burning,gasoline and die