Abstract: Semipermeable membrane devices (SPMD) were deployed in the Pearl River Delta (PRD), South China, to monitor the seasonal variations of organochlorine pesticides (OCPs) in the air for a year. Results showed that the OCPs compounds in the sampling areas were mainly DDTs, HCHs, chlordane and methoxychlor. DDTs in all samples comprised 62% to 88% of the total amount of OCPs. The distributions of OCPs in the air were characterized by temporal and spatial difference in the PRD. The OCPs concentrations were higher in the summer than in the winter. The annual average concentrations of OCPs ranged from 3.8～27.5 ng/d in different areas, with lower values in Hong Kong and Zhuhai (averaged 5.0 ng/d) and higher values in Guangzhou (GZ01, averaged 27.5 ng/d). The high ratio (>1) of m(DDT)/m(DDD+DDE) possibly indicated that there were still fresh DDT emitted into the atmosphere. The annual average enantiomeric compositions (ER(+/-)) of α-HCH and α-Chlordane were 0.75 and 0.69, respectively. The ER(+/-) value of α-HCH in the air was equivalent to that in the soil in the summer but lower than that in the winter. It is suggested that the atmospheric α-HCH in the summer were mainly from soil evaporation, while transported α-HCH may contribute significantly in the winter.