Recycled tire wastes mixed with soils are applicable as lightweight filling material for slopes, sub-bases of pavements and retaining walls to improve the safety of the retaining walls. Under the seismic loadings, e.g., earthquake or traffic loads, the dynamic responses of granulated rubber/soil mixtures, such as the evolution of stress-strain, rule of cumulative pore water pressure, dynamic shear modulus, and liquefaction resistance, are essential in the design of such a system. This paper investigates the dynamic responses, liquefaction resistance mainly, of recycled rubber tire powder through mixtures with different tire powder sizes in saturated condition using cyclic triaxial tests. The results show that the larger tire powder size significantly improved liquefaction resistance of granular materials. Meanwhile, the incorporations of tire powder changes the deformation pattern and the evolution of pore water pressure compared to the pure sand. The attempt is to further explain the evolved dynamic behavior of the mixture. And the results as a supplement enrich the database of dynamic behavior of soil rubber mixture as lightweight filling material in saturated condition. Finally, the results are interpreted from the microscopic view of the point.