Objective: In the present study, the effects of progressive body weight support treadmill forward & backward walking training (FBWT), progressive body weight support treadmill forward walking training (FWT), and progressive body weight support treadmill backward walking training (BWT), and on stroke patients’ ambulatory abilities were examined. Design: Randomized controlled trial. Methods: A total of 36 chronic stroke patients were divided into three groups with 12 subjects in each group. Each of the groups performed one of the progressive body weight supported treadmill training methods for 30 minute, six times per week for three weeks, and then received general physical therapy without any other intervention until the follow-up tests. For the assessment of the step length, total double support, cadence, gait were measured using optogait and the 10-m walk test (10MWT), 6 minutes walk test (6MWT). Results: In the within group comparisons, all the three groups showed significant differences between before and after the intervention (p<0.05). In the comparison of the three groups, there were significant differences among the three groups in stride length, double limb support stance, cadence, 10MWT, and 6MWT in the third week, and only in stride length, 10MWT, and 6MWT test in the sixth week (p<0.05). Conclusions: This study verified that progressive body weight-supported treadmill gait training positively affected the gait ability of stroke patients in an actual gait environment. It also showed that FBWT group was more effective than FWT group and BWT group training.