Reflexes have been viewed as an integrated motion with the centrally generated motors commands to produce adaptive movement. In this paper, the reflexes that highly adapt and control the movement of the humanoid robot when a large disturbance occurs is considered. The structure of the reflex system is proposed combined with the walking motion generator. Our approach to generate a rhythmic motion does not require complex dynamics models. It is based on linear oscillators and provides flexibility in introducing reflexes. In order to demonstrate the effectiveness of the proposed system, the humanoid robot HOAP-3 of Fujitsu is used. It is shown that a reflex movement is successfully integrated with the rhythmic motion in the following case; sudden change in the floor level, sudden change in load, and presence of a large disturbance. As a result, the proposed reflex system contributes toward the safe interaction of the humanoid robots with the environment.