We fabricate Bi2Sr2Co2Oy films on c-Al2O3 by pulsed laser deposition and investigate the effects of substrate temperature and oxygen pressure on the crystal stucture and the transport properties of the films. The resulting single phase c-axis Bi2Sr2Co2Oy films obtained under the optimal condition have a room temperature resistivity of about 2.9 m/cm and a seebeck coefficient of 110 V/K, leading to a larger power factor than that of the single crystal. In addition, a negative magnetroresistance of 40% at 2K and 9T is observed in the films.