Abstract: A semi-active predictive control (SAPC) scheme with magnetorheological (MR) dampers for reducing the responses of seismically excited structures is developed, which can predict the future multi-step responses of structures according to the current state. The scheme is based on a prediction model of the system response to obtain the optimal control actions by minimizing an object function, which has a function of self-compensation for time delay that occurred in real application. As an example, a 5-story building frame equipped with 2 MR dampers is presented to demonstrate the performance of the proposed SAPC scheme for addressing time delay and reducing the structural responses under different earthquakes. Results indicate that the SAPC strategy can guarantee the stability of the controlled structure and reduce the bad effects of time delay on the controlled system even though the delayed time reach 1.0 to 2.0 seconds.