Our developing Gait Training System is the training device that tries to obtain the effect similar to the walk training in the warm water swimming pool. A train patient is slung and supported by the slinging system. They walk the force plate top. Slinging it up power is controlled on the basis of the information from the force plates. In this paper, we show the outline of our system and improvement of sling mechanism using bilateral servo system. Next, method and application of force measurement is shown and development of visual feedback function of trainee's foot contacted point and target contact point is shown.