Poly(vinylideneflouride-hexafluoropropylene) (PVDF-HFP) copolymer films were simultaneously stretched and static electric poled (SSSEP) in seriate mode. The experimental results exhibited that SSSEP greatly enhanced the piezoelectric properties of the PVDF-HFP films and slightly increased the dielectric properties of the films. The maximum piezoelectric coefficient d(33) 24 pC/N higher than the reported was obtained in these films under optimum condition. Based on the wide angle X-ray diffraction results, the SSSEP films showed more organized crystalline structure than the only stretched films.