Surface sintering of skived poly(tetrafluoroethylene) membrane was carried out to improve the water permselectivity of the membrane. The surface morphologies of the modified and unmodified membranes were studied by scanning electron and atomic force microscopy. The results indicate that the surface sintering process can make the surface denser and smoother, resulting in higher water permselectivity but lower permeation rate. In addition, the vapor permeation performances were strongly related to the surface resintering temperature.