Abstract: The high temperature and low temperature performances of rubber modified asphalts with different viscosity reducers(1%, 2% and 3%) were studied by means of dynamic shear rheological test(DSR) and the bending creep test (BBR).The results indicate that the viscosity-reducer LP improves the high temperature performance of the rubber modified asphalt, in which the phase angle decreases and the complex modulus increases, and its high temperature performance increases gradually with the increase of viscosity reducers.Mixed with LP viscosity-reducer improves the low temperature performance of rubber powder modified asphalt, but the low temperature property decreases by the increase of viscosity-reducer dosages, which have the negative effects on improvements. The improvement effect on low temperature of viscosity agent LP to the rubber asphalts reduces with the temperature reduction, and the improvement of the low temperature performance with different dosages is similar.