Multi-walled carbon nanotube(MWNT)-polyurethane block copolymer(PU) nanocomposites were prepared, and their electroactive shape recovery characteristics were investigated. The nanocomposites incorporating chemically modified MWNTs showed higher modulus and breaking stress than those incorporating raw MWNTs, which was ascribed to an increased dispersion of nanotubes in the matrix polymer and increased interfacial strength between nanotubes and polyurethane molecules. However, their electrical conductivity decreased with the degree of chemical modification of MWNTs. The best properties were obtained in the composites incorporating MWNTs modified at $90^{circ}C$ on basis of combined evaluation of mechanical and conducting properties. Good electroactive shape recovery within 10 seconds was obtained when a voltage of 10 to 30 V was applied to the composites of $3-7wt\%$ modified MWNT content.