This study is concerned with the characteristics of the radial jet flow which reattaches on a rotating disk. The velocity fields near the side wall and in the jet were measured to clarify the variation of the basic characteristics of the mean flow. As the step height becomes high, the reattachment position of the jet moves to the upstream side depending on the increase of the disk rotating speed. The maximum velocity and the jet half-width change like the radial free jet until reattaching on a disk, and they show the change similar to the radial wall jet after the reattachment.