Abstract: The contents of sixteen organochlorine pesticides (OCP16) in surface sediments of seawater, surface seawater and microlayer seawater, respectively, in Dalian Bay were determined by capillary GC-ECD method. The results show that recovery rate of OCPs determination by capillary GC-ECD is high, coefficient of variation of response factor small and detection limit low, and the method is fit for the determination of OCPs in marine environment samples. OCPs in both sediment and seawater in Dalian Bay are detected, but pollution level is relatively low. The average concentration of OCPs in surface seawater is 4.52 ng/L, and OCPs in surface seawater sediment is 6.17 ng/g. The contents of OCPs in microlayer seawater are much higher than those in surface seawater, which indicates that there is strong enrichment of OCPs into microlayer seawater and the average enrichment factor is among 5.1～15.4.