The influence of thermal treatment and cold drawing was investigated for poly(ethy1ene terephthalate) films fabricated with various experimental conditions. Samples were elongated at room temperature under stepwise-drawing condition with the cross-head speed kom 0.5 to 500 mrdmin in an universal tester. Stress oscillation was observed in the stress-stnin curve of the samples heat-treatd at 50, 72 and $129^{circ}C$ for 30 min, but it was not observed in the samples heat-treatd at $83^{circ}C$ for 30 min. Thermal analyses of the samples were carried out in differential scanning calorimeter at the heating rate df $10^{circ}C$/min/min, and the glass transition temperature, crystallization peak, enthalpy of fusion and degree of crystallinity were measured. The dynamic mechanical analyses of the samples were also carried out in a multiplefimction internal kiction pendulum at 1 Hz with the heating rate of $1.5^{circ}C$/min, and it was found that the elastic modulus increases in the order of non-treated, heat-treated, and elongated samples.