A novel porous membrane, based on a polymer matrix of poly(acrylonitrile-polyhedral oligomeric silsesquioxane) (P(AN-POSS)), is prepared by phase inversion process, and the corresponding gel polymer electrolyte (GPE) is further fabricated by immersing the porous membrane into liquid organic electrolyte. The thermal stability and structure of prepared POSS and polymers are investigated. The research indicates that the P(AN-POSS) membrane with copolymerization content of 8 wt% POSS exhibits the better pore structure and superior electrolyte uptake compared with pure PAN membrane, which endows the corresponding GPE with remarkable comprehensive performances: the maximum ionic conductivity value of 6.06 x 10(-3) S cm(-1) at ambient temperature, the sufficiently stable interface compatibility between GPE and electrode, the excellent lithium ion transference number of 0.59 and the higher electrochemical stability potential of 5.7 V (vs. Li/Li+). At 0.2 C, the GPE with 8 wt% POSS in polymerization based lithium ion battery shows a satisfactory discharge capacity of 148 mAh g(-1) and improved capacity retention of 93.7% after 80 cycles.