In this study, the SMG fluid was developed for compensating the defect of the MR Fluid that is commonly used in Semi-active control system. And the damper with SMG fluid have been developed for practical application. The dynamic load test was conducted to evaluate the control performance of the SMG damper at 0.5Hz and 1Hz frequency conditions and 0A and 0.5A current conditions. As a result, the remarkable performance of the SMG damper was verified.