The gas content is one of the important bubble parameters. In this article, the gas content effect on the bubble motion is investigated by numerical simulation based on the spherical bubble model. The dependence of the bubble radius, oscillation velocity and the corresponding bubble energy on the gas content during the bubble pulsation is analyzed in detail according to differential equations of the bubble dynamics. The numerical calculations are shown that with the gas content remained in a cavity increasing, the corresponding bubble radii become larger. Further, both the maximum bubble radius and bubble energy show approximately linear-relation with the gas content during the first oscillation cycle, while in the second pulsation period they are observed non-linear with the gas content. In addition, with the gas content increasing, the bubble expanding and contracting velocities are both decreased, whereas the corresponding oscillation periods at the first two oscillations are obviously prolonged.