The dynamic analysis of earthquake responses of one simple bridge structure supported by hinged and rolled bearing and another simple bridge structure isolated by lead-core rubber bearings was described in elastic-plastic range. The relative displacements and accelerations of the structures were calculated under different amplitude earthquake waves in order to observe the influence of lead-core rubber bearing on earthquake- resistance of bridges. The availability of the analysis model, hysteretic model and relevant parameters adopted as well as the computation program developed are verified. According to the analysis of dynamic response data, the lead-core rubber bearings with proper parameters are used to improve the dynamic performance of the structures, the seismic response of the bridge deck and pier would therefore be greatly reduced, the safety and seismic performance of the structure are globally raised, earthquake- resistance could be increased, and rather good economic benefits have been achieved as well. The analysis can provide accurately the reference basis for construction design.