Gas and particle samples were collected by a high-volume sampler from July 2009 to March 2010 at an eastern regional background site in Ningbo and analyzed for polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). The total (gas + particle) air concentrations of 11 OCPs ranged from 5.34 to 417 pg/m3, of which HCHs, DDTs, chlordane and HCB concentrations ranged from 0.67 to 214 pg/m3, 2.03 to 198 pg/m3, 2.25 to 158 pg/m3, and 0.38 to 77.1 pg/m3, respectively. The total concentrations of PCBs ranged from 42.4 to 224 pg/m3, with an average of 102 ± 53.6 pg/m3. Similar seasonal trends of HCH, DDT, chlordane, HCB concentrations were observed with the winter maximum. Diagnostic ratios indicate that aged technical HCH, DDT and chlordane were the major source of HCHs, DDTs and chlordane, respectively. PSCF analysis identified that northern China, southern China and Japan were major source regions of OCPs at Ningbo background site. As for PCBs, the seasonal trend was characterized with higher concentrations in summer. Those compounds were mainly influenced by the sources nearby and soil volatilization.