Abstract: The fuzzy logic control method based on Takagi-Sugeno model is proposed for controlling structural vibration by semi-active friction damper installed on a nonlinear building structure subjected to earthquakes. The equation of motion for nonlinear building structure with continuous Bouc-Wen hysteretic model is firstly introduced. Next, the initial sliding force with friction damper is determined by time history analysis under minor earthquakes. And then, the Takagi-Sugeno fuzzy logic model is employed to adjust the normal force acted on the friction damper according to the semi-active control strategy. Numerical simulation results demonstrate that the proposed method is very efficient in reducing the peak acceleration and inter-story drift of the nonlinear building structure under earthquake excitations.