In this paper a robust adaptive pole placement method for a class of linear parameter varying (LPV) system based on input-output description is constructed after the LPV system model, including its un-modeled error model term, is presented. The recursive least square estimation algorithm with dead zone is applied for the parameter estimation. The robust stability of closed-loop system is analyzed and the robust bound is derived. One simulation example illustrates the effectiveness of the control algorithm and demonstrates that the adaptive control based on LPV model can achieve better performance than the controller based on linear time varying (LTV) model.