In this paper, a front-steering assist control is designed to stabilize a motorcycle during braking. The rider-motorcycle system with its pitching motions is linearized around an equilibrium point of quasi-steady state straight running with constant deceleration. From the viewpoints of eigenvalues and frequency responses, the linearized model is analyzed and a reduced-order model is obtained to design the control system by using H. control theory. By carrying out simulations during braking, it is demonstrated that the control system can stabilize a motorcycle when receiving a sudden disturbance from the front wheel and is robust against parameter variations and several braking situations.