Municipal solid waste (MSW) source-classified collection represents a change in MSW management in China and other developing countries.Comparative experiments were performed to evaluate the effect of a newly established MSW source-classified collection system on the emissionof PCDDs/Fs (polychlorinated dibenzo-p-dioxins and dibenzofurans) and heavy metals (HMs) from a full-scale incinerator in China. As a result ofpresorting and dewatering, the chlorine level, heavy metal and water content were lower, but heat value was higher in the source-classified MSW(classified MSW) as compared with the conventionally mixed collected MSW (mixed MSW). The generation of PCDDs/Fs in flue gas from theclassified MSW incineration was 9.28 ng I-TEQ/Nm3, only 69.4% of that from the mixed MSW incineration, and the final emission of PCDDs/Fswas only 0.12 ng I-TEQ/Nm3, although activated carbon injection was reduced by 20%. The level of PCDDs/Fs in fly ash from the bag filterwas 0.27 ng I-TEQ/g. These results indicated that the source-classified collection with pretreatment could improve the characteristics of MSW forincineration, and significantly decrease formation of PCDDs/Fs in MSW incineration. Furthermore, distributions of HMs such as Cd, Pb, Cu, Zn,Cr, As, Ni, Hg in bottom ash and fly ash were investigated to assess the need for treatment of residual ash.