A total of 176 sets of PM10 samples have been collected at five automatic stations of air quality monitoring network in Hangzhou city from February 2001 to April 2002. The concentrations of organic carbon(OC) and elemental carbon(EC) have been analyzed. The mass concentration of PM10 have been analyzed synchronistically by TEOM method，the mass concentration of PM2.5 have been also analyzed in Wolongqiao automatic station. The annual average daily concentration of PM10 is 119.2mg•m-3，and of PM2.5 is 68mg•m-3.The relationship between the mass concentrations of PM2.5 and PM10 is obviously linear .The ratios of average 24-h PM2.5 to PM10 concentrations range from 0.31 to 0.95 ,the average ratio is 0.62. The average concentrations of OC and EC are 20.4 mg•m-3 and 4.0 mg•m-3 , respectively. The relationship of OC and EC is not good, implying the complex sources of OC and EC. Secondary organic carbon (SOC) accounting for 37.2% amount of OC in Spring,, 47.0% in Summer, 57.8% in Autumn and 43.7% in Winter, indicating the presence of secondary organic aerosols in atmosphere of Hangzhou.