Abstract: Liquid crystalline polymer blended gas separation membranes are obtained by melting and processing 50˜99 wt % of a thermoplastic resin, 1˜50 wt % of a thermotropic liquid crystalline polymer and 0.1˜10 wt % of a compatibilizer based on the weight of the thermotropic liquid crystalline polymer. A method for fabricating liquid crystalline polymer blended gas separation membrane includes the steps of: mixing 50˜99 wt % of thermoplastic resin, 1˜50 wt % of thermotropic liquid crystalline polymer and 0.1˜10 wt % of compatibilizer based on the weight of the thermotropic liquid crystalline polymer; and biaxially extruding the resulting blend melt from an extrusion die of a film blowing apparatus to fabricate a film. The gas separation membrane exhibits high permeability exceeding the limit value which has been hardly overcome by the existing separation membranes.