Abstarct: Magnetorheological fluids (MRFs) are type of smart materials that its rheological properties change with applying magnetic field. These fluids due to the yield stress and controllable viscosity have vast applications such as dampers, electronic clutches and rotary brakes, medical instruments, polishing and,… hence in a past two decades numerous studies have been performed on fabrication and application of MRFs. Magnetorheological fluids construct from dispersion of magnetizable particles into carrier fluid. Because of density mismatch between particles and carrier fluid, Stabilizer will be added to MRFs, nevertheless MRFs stability is the main problem on these fluids development. The other usage problem of MRF is considerable effect of temperature on rheological behavior, since it is generally works in small container with large heat generation. In this study various kinds of MR fluids were made. These samples were compared in term of sedimentation. Because of high heat capacity Silicon oil for reduction of temperature effect on rheological behavior were used for MRF samples fabrications. The relation between MRF yield stress and applied field and temperature are presented. Design, evaluate the performance and control of the magnetorheological damper need an appropriate dynamic model. Types of presented model for the magnetorheological damper can be categorized into two classes: phenomenological and physical modeling. Phenomenological models need to damper fabrication and experiment to parameter identification but physical models are only dependent to geometrical properties of the damper and fluid properties. For this reason these models are appropriate to design phase. Mixed mode MR dampers due to high force capacity and suitable performance on all piston velocity (even in low velocities) are suitable for vehicles applications. For the first time dynamic modeling of the mixed mode MR damper with considering inertia term was done in this study and in addition considering temperature changes in modeling process is considered. Despite of importance of considering temperature duo to high changes of temperature of working MRF, few study have been considered temperature in a dynamic model. In order to represent efficiency of MR damper into passive suspension system, Sky- Hook control logic was applied to one quarter vehicle model. A comparison between passive and semi active suspension with magnetorheological damper including Sky- Hook controller have been performed.