With the development of the computational technology, vehicle dynamics simulation has become a powerful tool for vehicle design in automotive industry nowadays. Since the tire plays a crucial role in vehicle handling, ride comfort, and durability, an accurate and efficient tire model becomes the prerequisite for the reliability and effectiveness of various vehicle dynamic simulations. In this dissertation, first an in-plane flexible ring tire model which is mainly used for straight line ride comfort and durability analysis is proposed. The model consists of a rigid rim, a certain number of discretized lumped mass belt points and massless tread blocks attached on the belt. Various virtual in-plane cleat tests according to the commercial ADAMS® FTire are conducted for parameter identification and validation of this in-plane tire model. The in-plane flexible ring tire model is further extended to a 3D out-of-plane tire model with a broader range of applications. The parameters in the 3D out-of-plane tire model are divided into in-plane tire parameters and out-of-plane tire parameters. Within the 3D tire model the values of the in-plane tire parameters are borrowed directly from the in-plane tire model, and the out-of-plane tire parameters are identified based on certain out-of-plane cleat tests. Various ADAMS® FTire driving/braking, cornering and cleat tests are conducted to validate the proposed 3D out-of-plane tire model. Besides, several important topics regarding to the flexible ring tire model, including the tire model efficiency, tire parameter sensitivity, robustness of the parameter identification procedure, and the relation between the tire parameters and tire model discretization, are also investigated in this dissertation.