[Purpose] The purpose of the present study was to examine the effect of strength training using a sliding rehabilitation machine (SRM) on the gait function of cerebral palsy children. [Subjects and Methods] Thirteen children aged 6–18 years participated in the SRM training for 8 weeks (30 min/day, 2 times/week). The SRM is designed for the performance of a closed-kinetic chain exercise in which a tilt table is moved up and down using wheels on the table. Participants began in a position of flexion of the 3 lower joints (hips, knees, and ankles) on the SRM. In each exercise session, they extended and flexed the 3 joints. The level of exercise was set by changing the inclination of the tilt table. Functional gait ability was measured with the 6-minute walk test (6MWT), 10-m walk test (10MWT), and timed up-and-go test (TUG) before and after the training. Muscle strength was also measured using an isokinetic dynamometer. [Results] Nine of the thirteen children completed the entire study. The peak torques of the knee extensor and flexor group muscles significantly improved after training with the SRM. The total distance of the 6 MWT significantly increased after training. The times of the 10 MWT and the TUG significantly improved after training. The changes in muscle tone were also investigated using the MAS (Modified Ashworth Scale) and Tardieu scale, but no significant changes were found in muscle tone between the pre- and post-test measurements. [Conclusion] The findings demonstrate the effect of the SRM intervention which resulted in improved muscle strength and functional gait.