Molybdenum (Mo) thin films were deposited on soda-lime glass substrate by using RF magnetron sputtering. As is well known, base pressure in sputtering is a processing parameter for preparing high quality Mo films, in addition to RF power and working pressure. The structure, surface roughness and electrical resistivity of Mo thin films were investigated at three base pressures of 1.8×10-7, 5.8×10-7and 2.7×10-6 torr. Experimental results indicate that the Mo films deposited at a low base pressure of 1.8×10-7 torr exhibit a low electrical resistivity of 8.910-6 –cm, a low root mean square value of roughness of 4.92nm and a stronger peak intensity of (110) plane than that of the other two pressures. This finding suggests that Mo films sputtered at a low base pressure have higher crystallinity, larger grain size, smoother surface morphology and lower electrical resistivity than those sputtered at a high base pressure.