Abstract: Based upon the practical situation of raw materials and equipments inChina the smoke suppression action and flame retardancy of flexible PVC formula-tions blended with some sorts of metallic compounds and fillers were comparedand scrutinized in the paper by means of parameters derived from NBS smoke box.The result shows that the smoke density and the ratio of smoke production aregreatly decreased and the time of smoke production is obviously retarded afteradding ATH. CaCO_3 is disadvantageous to the flame retardancy of flexible PVC,but it is of benefit to smoke suppression. Adding metallic compounds can makelittle effect on the LOI values of flexible PVC, but it greatly affects the smokedensity, especially the copper compounds. The flame retardancy and smoke suppres-sion of flexible PVC is obviously increased after adding both filler and metalliccompounds.