In this paper, an adaptive fuzzy-sliding control system is proposed to improve the dynamic performance of a three-phase active power filter (APF). Adaptive fuzzy controllers are employed to approximate both the equivalent control term and the switching control term in the sliding mode controller. An online adaptive tuning algorithm for the consequent parameters in the fuzzy rules is also designed. The switching control becomes continuous and the chattering phenomena can be attenuated. Simulation demonstrated that the proposed control method has an excellent dynamic performance such as small current tracking error, reduced total harmonic distortion (THD), strong robustness in the presence of parameter variation and non-linear load.