Based on the LuGre dynamic friction model,a model reference adaptive controller (MRAC) is proposed to solve the vibration isolation problem of frictional structures with undetermined parameters. The dynamic model of the single-degree-of-freedom (SDOF) frictional structure is established using the LuGre dynamic friction model to describe the friction force. With choosing the ideal Skyhook structure as the reference model, a dual-observer is used to estimate the state of the friction, and a MRAC active controller is designed. It is proven by the Lyapunov method that the closed-loop system is asymptotically stable, and that both the displacement tracking error and the velocity tracking error converge to zeros. The simulative study is carried out and the results show that this kind of controller not only greatly decreases the response of frictional structures near the resonance frequency, but also improves the system’s vibration isolation performance at higher frequency.