High speed train operation on narrow-gauge lines requires high deceleration for brakes, even when a lubrication film of rain water exists on the rail. In other words, high adhesion force is needed between wheel and rail. We applied high adhesion and high deceleration brake by a "multiple-mode slide/re-adhesion control method" to 681 series EMU whose mechanical brake system mainly consists of brake-disks, and analyzed behaviors of the coefficient of traction. The analysis shows that the coefficient of traction behaviors differently depending on the roughness of wheel tread. Accordingly, we developed re-adhesion control method in accordance with the roughness of wheel tread. The fact verifies we can obtain high adhesion force even when rain water exists on the rail.