The characteristics of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and chlorobenzenes (CBzs) in flue gas and fly ash at the outlet of the furnace, outlet of the high-temperature superheater, inlet of the semi-dry scrubber and the stack after the APCD has been studied. Both PCDD/Fs and CBzs were mostly formed at low temperatures. The dominant PCDD/Fs generated in the gaseous phase were 23478-PeCDF and TCDF, and 124-TrCBz was the major CBz in both gaseous and solid phase. More PCDD/Fs were found in the solid phase with the decrease of temperature, while CBzs were at the opposite trend. Furthermore, activated carbon with low surface area and mesoporous volume showed low flue gas removal efficiencies of PCDD/Fs and CBzs in flue gas. The fraction of PCDD/Fs in the solid phase largely decreased when the flue gas passed through the fabric filter. And the memory effects of aged filter could also cause increasing fractions of 234678-HxCDF, 1234678-HpCDF and 1234678-HxCDD. Most importantly, the relationships between PCDD/Fs and CBzs in the flue gas and fly ash were analyzed, respectively. In the gaseous phase most of CBzs showed high correlation coefficients with PCDD/Fs, especially 123-TrCBz (R2 > 0.8). In solid phase the poor correlation coefficients were found between CBzs and PCDD/Fs except 135-TrCBz and 123-TrCBz (R2 = 0.8). A remarkable correlation was also found between 124-TrCBz in flue gas and PCDD/Fs in fly ash. It was concluded that TrCBzs could be regarded as the best indicator for PCDD/Fs in both flue gas and fly ash.