Active control of vibration has been the subject of a lot of research in recent years. Adaptive linear filtering techniques have been extensively used for the active control of vibration. A popular adaptive filtering algorithm is the filtered-X LMS algorithm because of its simplicity and its relatively low computational load. However, the filtered-X LMS algorithm is limited to linear control problems using feedforward control techniques. A fuzzy logic system based control structure and adaptive algorithm suitable for driving non-linear feedforward active vibration control systems is presented in this paper. This kind of non-linear fuzzy control method is used in two kinds of active vibration control problems, as follows: (1) A fuzzy logic system is used to approximate a non-linear sensor path function and to suppress the primary disturbance that is a non-linear function of the reference signal. (2) A fuzzy logic system is used in active control of vibration with non-linear piezoelectric actuators. The numerical simulation results show the effectiveness of this adaptive fuzzy control method.