Micro structures and electrical properties were investigated on thin films crystallized from amorphous Y-Ba-Cu-O film prepared by rf-sputtering. Effects of fluorine or CuO addition to the amorphous film were also studied on these properties. An elevation of crystallization temperature enhanced both platy YBCO crystal growth and its orthorhombic c-axis preferred orientation in the crystallized film on MgO substrate. Sputtering power was more important on the film / SrTiO₃. No preferred orientation was observed on the film prepared at 100W power. Larger rf-power and fluorine addition to sputter target elevated substrate temperature (Ts). Epitaxially preferred oriented films were obtained at Ts≥350°C. Amorphous films containing fluorine or excess CuO gave c-axis preferred orientations at annealing temperature of 50°C lower than that of Y-Ba-Cu-O film. CuO added film showed the best result on superconducting transition (Tc zero≥70 K) in the present investigations.