The paper addresses the control issue for wing-rock motion of slender delta wings. Wing-rock motion is a self-excited limit-cycle oscillation at high angles of attack. Experiments shown that hysteresis provides clues about where the motion is being driven and damped. Generally, the effects of hysteresis for moment coefficient vs. roll angle can be treated as a combination of phase and magnitude distortion. To suppress the wing-rock, hysteresis compensator, so-called phaser, is adopted to eliminate this hysteresis. The phaser, an inverse phase function of the hysteresis, can be approximated by a linear filter. Furthermore, a variable phaser control scheme is designed to handle multi-loop hysteresis. The final synthesis scheme combines the variable phaser and P control to accelerate the wing-rock attenuation. The effectiveness of the proposed scheme is demonstrated by the control of wing rock at different angles of attack.