Anionie monofunctional polymerization and difunctional Polymerization of HFPO with perfluorinated acyl fluoride in presence of potassium fluoride have been studied．We found that under ordinary pressure the activity of monofunctional polymerization of HFPO in presence of potassium fluoride is much smaller than that in pre-sence of cesium fluoride reported in the literature，and in the presence of potassium flnoride the activity of difunctional polymerization of HFPO is larger than that of mono-functional polymerization．We also found that the emulsified layer formed at the end of the polymerization shows catalytic activity．it may has the composition of K+- OCF2RfCF2-O-K+．It catalyses the monofunetional polymerization of HFPO during the difunctional polymerization．A mechanism is suggested to explain this catalytic phenomenon．