The resistive transition of high-Tc superconducting films in various magnetic fields has been measured at temperature near Tc. There is a broadening of the resistive transition in magnetic fields. The broadening of the resistive transition was analyzed with the flux creep theory of Anderson-Kim. We found the activation energy is temprature, magnetic, angle and thickness dependent. We obtained the activation energies which are 60 meV, 23 meV, 7 meV and 12 meV for YBCO film with 15 % Ag impurities, YBCO film, ultrathin YBCO film (35nm) and BSCCO film respectively in a field parallel to the ab plane in H = 5.0 T and at T/Tc = 0.93, where Tc is the onset superconducting transition temperature.