Cu films with thickness of about 500nm were deposited on glass substrates without heat-ing by DC magnetron sputtering in pure Ar gas of 1.0Pa. The sputtering powers weremaintained at 390V× 0.27A, 430V× 0. 70A and 450V× 1.04A, and the correspondingdeposition rates of Cu film reached 35nm/min, 104nm/min and 167nm/min. X-raydiffraction, scanning electron microscopy and atomic force microscopy were used toobserve the structural characteristics of the films. The resistance of the films was mea-sured using four-point probe technique. The amount of larger grains increases and theresistivity of the films decreases evidently with an increase in sputtering power. It isconsidered that the increase in deposition rate with sputtering power mainly weakensthe influence of residual gas atoms on the growing film, and increases substrate andgas temperatures, resulting in the increase in grain size and the decrease in resistivityof the Cu film.