The ferroelectric phase transition was investigated in the blends of vinylidenefluoridetetrafluoroethylene (VDF-TFE) and vinylidenefluoride-hexafluoroacetone(VDF-HFA) copoly-mers using X-ray diffraction, infrared spectroscopic and differential scanning measurements. All the samples prepared except pure VDF-HFA copolymer showed the ferroelectric transition well. The ferroelectric-paraelectric phase transition temperature was over a broad temperature range and complete transition finished with its melting. The transition from ferroelectric phase to paraelectric seemed to occur without passing through the intermediate phase which was shown in vinylidenefluoride-trifluoroethylene copolymer. The paraelectric-ferroelectric phase transition of blends was found only at a cooling rate less than at least 5˚C/min from the melt and this transition was due to that of VDF-TFE copolymer because of crystallization behavior in the blends.