Abstarct: The objective of this research is design and fabrication of smart damper with megnetorheological (MR) hydraulic oil. In this thesis the MR fluid used in MR damper is synthesized first. The sedimentation test and rheometry test in shear and oscillatory modes are implemented. Careau-yasuda model is used for modeling of the rheometry test results in this research. Also rheometry test results is used for obtaining generalized MAXWELL model coefficients. In the next step MR damper is designed and geometrical and hydraulic parameters is derived with the aid of fluid rheometry test results and shock absorber specifications of TIBA car. In order to obtain magnetic parameters required for damper construction, ANSYS-MAXWELL software has been utilized. In the construction of damper, two-dimensional drawings of all parts have been supplied with SOLIDWORKS 2013 software and all parts have been constructed with great precision. Force tests of MR damper have been utilized with the cooperation of INDAMIN SAIPA Corporation in two velocity of 0.05 m/s and 0.1 m/s and three modes as follows: without application of electric current, with 3 A and with 4 A application of electric current to the damper winding. The results of these tests show that the constructed MR damper increases damping force in comparison with conventional shock absorber of TIBA car as follows: in the velocity of 0.05 m/s and 3 A current damping force augmentation is 26%, in the velocity of 0.05 m/s and 4 A current damping force augmentation is 70%, in the velocity of 0.1 m/s and 3 A current damping force augmentation is 93% and in the velocity of 0.1 m/s and 4 A current damping force augmentation is 150%.