A brief description about designing of Magnetorheological (MR) damper are described. MR dampers are semi-active suspension devices that use MR fluids to produce a controllable damper. The mechanical properties of the suspension can be controlled by adjusting the yield stress of the MR fluid. In this book, the design development for a new mixed mode MR damper with combination of shear and squeeze working modes was carried out. The magnetic field generated by electromagnetic coils in MR damper was analyzed using finite element method. The MR damper was designed and fabricated based on the simulation results. Combination of process parameters of working modes condition and applied current under quasi-static loadings were used in the experiments. Results, the unique damping characteristics of mixed mode MR damper was found where in general, a higher damping force has obtained in mixed mode than single mode. Eventually, the design of MR damper will provide an opportunity to study and consequently understand on how the MR fluids react to such operating condition in order to be realized in the MR damper.