A novel composite microporous polymer elec- trolyte composed of poly(vinylidene fluoride-co-hexafluorop- ropylene) (PVdF-HFP) and mesoporous SBA-15 was pre- pared. The composite solid polymer electrolyte (CSPE) ex- hibits ionic conductivity as high as 0.30 mS·cm?1 with a composition of SBA-15︰PVdF-HFP=3︰8 at room tem- perature. Infrared transmission spectroscopic results sug- gested that the mechanism of micropore formation is similar to that of the phase inversion. X-ray diffraction (XRD) results demonstrated that the addition of SBA-15 inhibits the crys- tallization of PVdF-HFP, while the SBA-15 preserves well its ordered mesoporous structure during the course of prepara- tion. The Li/CSPE/MCF of half-cell was assembled, and it showed a good electrochemical and cyclability performance during charge-discharge cycles.