The aim of this study, design and fabrication a prototype of double-tube magnetorheological damper (MR damper) involving micron sized and soft ferro magnetic of carbonyl iron (CI) particles and stabilizer nanoparticles of silicone (SiO2). Whiles initially magnetorheological fluid as its application and required, designed and fabricated. Then sedimentation and magnetorheometry tests (in mode of shear) was done. That the resulting of sedimentation test, illustrated that after 10 days, the value of sedimentation just was 15% and maximum of shear stress in maximum current was about 20kpa, that was desired. Then the magnetic section of the research, was conducted using the existing relationships and Maxwell software, at the end, using this data, the geometric dimensions of the MR damper, designed and fabricated. appropriate damper, was double tube type damper and at the combination of two valve and shear modes. After fabrication of appropriate damper, damping test was carried out on appropriate damper by damping test machine, that with regard to the receive graphs from test, at currents of 0 ,1 and 2 amps and speed of 0.05m/s, the magnitude of damping force aspect zero current(conventional damper), at saturate magnetic intensity (H_mr) was 5 times conventional damper. That was desired.