For expansion of adaptable sections of continuous welded rails, we should confirm the limit value of the gap of a rail breakage. The limit value of the rail gap was set at 70mm based on the running tests on a straight track and a fundamental study about condition of wheel/rail contact on straight tracks. On the other hand, examinations to justify this limit value on a high speed track or a curved track have not been implemented. The purpose of this study is development of a numerical dynamic simulation model that is capable of simulating the behavior of a vehicle at the time of its passing a rail gap. This study is concerned with a rail gap on a curved track in high speed railway. In order to construct the model, it is necessary to calculate the contact force between wheels and rails with high accuracy. For its purpose, this study uses a contact model using the finite element method to evaluate the wheel/rail contact force. The creep force necessary for verification of the simulation model was calculated using the analysis model to simulate the creep force characteristics test with use of full-scale wheelset, which incorporates the proposed wheel/rail contact model. Also running tests on rail gaps were carried out, to confirm the accuracy of the simulation model. The analyzed wheel load and lateral force and the result of these tests were in good agreement with each other. According to the results of verifications, the proposed simulation method is capable of simulating behavior of a vehicle at the time of its passing a rail gap with high accuracy. In conclusion, it is possible to clarify the relationship between rail gaps and rail contact forces with the newly developed method. In the future, we are planning to establish the limit values of the rail gaps with more improved accuracy of the simulation.