A magneto-rheological (MR) fluid mount based on disk squeeze mode was d esigned. The relationship between cycle dissipation powers of the MR mount and t he ex citing current was found at different exciting frequencies through experiments. A research model of engine vibration on semiactive control was established by us i ng the MR mount. A fuzzy logic control method was proposed. By means of rotation speed sensor, accelerometer, dynamic tension and pressure sensor, data acquisit ion and real time controller of national instrument, a fuzzy logic control syste m of engine vibration isolation was constructed. The experiment was carried out based on engine vibration isolation control under idle and common speed conditio ns. The experimental results show that dynamic exciting force transferred from the engine to the support can be decreased by using the fuzzy control syste m of MR mount and the effect of vibration isolation at the low speed is better than that at the high speed compared with the rubber mount.