Since the piezo-actuating system has hysteresis nonlinearity and time-varying characteristics, it is difficult to establish an accurate dynamic model for designing a model-based controller. Here, a model-free adaptive fuzzy sliding controller, which combines an adaptive rule with fuzzy and sliding-mode control, is employed to overcome the difficulty. The proposed control strategy has online learning ability in response to the system's nonlinear and time-varying behaviors during the control process. Tracking control of a piezo-actuating X-Y table using the proposed algorithm is investigated. Experimental results show that the proposed control scheme has good performances even with the presence of external disturbances. The experimental results are compared with those of a traditional model-based sliding mode controller and a fuzzy logic controller.