Nylon 6-ran-nylon 4 (100/0), (80/20), (70/30) films were prepared by using melt pressing methods. The (N6-ran-N4) films were annealed in the silicon oil bath at 50, 75, 100, 125 and 150 ˚C. The film properties were examined by WAXD, DSC, DMTA and moisture regain. The crystal structure in (N6-ran-N4) films increases the annealing temperature. This is very similar to the alpha phase of nylon 6. The thermal property of (N6-ran-N4) films annealed under high temperature exhibits an increase in the melting temperature and enthalpy. The moisture regain of (N6-ran-N4) films decreased when the annealing temperature was increased.