Nanofibrous membranes that possess reactive groups are fabricated by the electrospinning process from PANCAA solutions that contain MWCNTs. Field emission scanning electron microscopy is used to evaluate the morphology and diameter of the nanofibers. Potentials for applying these nanofibrous membranes to immobilize redox enzymes by covalent bonding are explored. It is envisaged that the electrospun nanofibrous membranes could provide a large specific area and the MWCNTs could donate/accept electrons for the immobilized redox enzymes. Results indicate that, after blending with MWCNTs, the diameter of the PANCAA nanofiber increases slightly. The PANCAA/ MWCNT nanofibrous membranes immobilize more enzymes than that without MWCNTs. Moreover, as the concentration of the MWCNTs increases, the activity of the immobilized catalase is enhanced by about 42%, which is mainly attributed to the promoted electron transfer through charge-transfer complexes and the p system of MWCNTs.