Passive walking is an attractive walking style which emerges autonomously on shallow slope without external input. It is known that the walking motion changes into chaotic in the vicinity of the limit of the stable walking. This phenomenon had been analyzed well, but isn’t utilized directly for control. Usually only period-1 walking gait is dealt with as an active usage of passive walking. In this paper, a strategy to enlarge the walkable range of passive walking by chaos control technique is presented. It is demonstrated by simulation that the walker can walk on more inclined slope and the levitation of legs is induced.