Polyaniline(PAN)/Polyimide(PI) blended membernes were prepared and the effect of mixing ration of PANI and PI on the stuctural properties and the gas transportproerties was studied. The polyamic acid(PAA) solution was prepared from 6FDAand ODA in NMP solvent. The PANI/PI blended membranes were obtained bymixing PAA solution and PANI solution. The gas permeation experiments with H_2,He, O_2,N_2,CO_2, and CH_4 were carried out by variable pressure method at 30℃ and5atm. For all gases tested, the permeability coefficient of OANI/PI blended membranes was higher relative to that of polyamiline and the separation factors for the blended were comparable to polyaniline.