A method was established for the determination of multi-components permeability of liquefied petroleum gas through polyethylene membrane by gas chromatography with a self made permeability apparatus.The method was optimized according to the membrane permeability mechanism as well as the characteristics of gas chromatography(GC),and the infiltration time and purging time were set at 15 min and 15 s,respectively.Good linearities for propane,iso-butane and n-butane were obtained in the range of 1.338-1.982×105,1.719-2.595×105,1.719-2.595×105 ng，respectively，with correlation coefficients（r2） of 0.999 0-0.999 6.The limits of detection for propane,iso-butane and n-butane were 0.472,0.534 and 0.692 ng，and the limits of quantitation were 1.573,1.779 and 2.307 ng,respectively.The relative standard deviations were less than 10% .Temperature was a major factor affecting the osmotic equilibrium and permeability coefficient.Under the same conditions,the permeability coefficient and penetration equilibrium time of the each alkane were different.The experimental results indicated that the developed method was simple,fast,and sensitive for the determination of membrane permeability under a condition of multiple gas coexistence.