Low-cost, responsive poly(N-isopropylacrylamide)/polystyrene composite films were prepared by a facile electrospinning technique. The surface structures and wettabilities of the composite films are tunable by simply controlling the concentration of polymer. With a proper proportion of each polymer, the wettability of the surface can be switched between superhydrophilicity and superhydrophobicity when the temperature is changed from 20 degrees C to 50 degrees C. The combination of a stimuli-responsive polymer with micro/nanostructures on the surface of the composite film contributes to this unique surface property.