Low resistivity is desired for the tungsten film used for the diffusion barrier, via and gate material in semiconductor devices. To achieve low resistivity, purity and film structure are the two factors needed to be controlled. It is known that higher the purity, better the performance of the tungsten film. On the other hand, it is not clear how the film structure that may effect the resistivity. In this study, we controlled the target density and ran a design of experiment for the sputtering power and gas pressure to obtain different film structures. Using the four-point probe, X-ray diffractometer and scanning electron microscope, the relationship between the film structure and resistivity was established. Key words: Tungsten, diffusion barrier, via, gate material, semiconductor, target density, Sputtering, film structure, resistivity.