Ambient air of Dalian was sampled with active high-volume air samplers in early spring time. The concentrations and the congeners between gas phase and particulate phase of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs) in the air were measured. Samples analysis results showed that the concentration of PCDD/Fs in particulate phase was higher than that in gas phase. The ratio of PCDD to PCDF in gaseous phase and particulate phase was lower than 0.4. The main sources of atmospheric PCDD/Fs in Dalian early spring season were coal-related source. The total I-TEQ in gaseous phase and particulate phase was 30.3 and 143.6 fg m-3, respectively. The I-TEQ of Dalian early spring atmosphere was lower than international standard, the atmospheric quality in Dalian was better.