Abstract:Air samples of thirteen sampling sites in Shenzhen were collected by the active high volume air sampler during December 2009 to January 2010 and June 2010. The PAHs in both air phase and particulates phase were analyzed, and the results showed that the concentrations of ∑PAHs in winter ranged from 17.9 to 92.3ng/m3, with average concentration of 45.3ng/m3, whereas in summer, the ∑PAHs concentrations scanned from 8.64 to 96.3ng/m3, with average concentration of 32.2ng/m3. The three to four rings PAHs occupied large proportion in all samples, which accounted for at least 75%. The concentration correlation analysis of monomers and ∑PAHs in two sampling periods demonstrated that the correlation in summer was better than that in winter. And the PAHs pollutants resources in winter were more complex than that in summer. The conclusion were also proved by the diagnostic ratio method, the oil and coal combustion, moter vehicles emission were the main resources in winter, but the main source in summer was only the motor vehicles emission. The toxic equivalence factor (TEF) and canceraganic risk assessment showed that the pollution of PAHs in Shenzhen city was still under a low level in comparison with other cities in China.