C-axis oriented zinc oxide thin films were deposited on Cornign 1737 glass substrate by an rf magnetron sputtering technique. The effects of deposition parameters and post heat-treatment on the crystallinity and electical properties of ZnO films were investigaed. As-deposited ZnO films showed the strong c-axis growth and excellent crystallinity under the deposition conditions as follows: substrate temperature 350$^{circ}C$ ; growth and excellent crystallinity under the deposition conditions as follows ; substrate temperature 350$^{circ}C$ rf power 75W ; gas pressure 6m Torr; percentage of oxygen 50% The higher heat-treating temperatue was the stronger c-axis growth and the better crystallinity of the deposited ZnO films were. The resistivity of ZnO films was significantly affected by deposition parameters and post heat-treatment. With increasing increased. After post heat-treating at 400$^{circ}C$ in air the resistivity of ZnO films increased but post heat-treat-ing temperature 500$^{circ}C$ rather diminished the film resistivity.