For an EMS-type Maglev vehicle, the levitation force is actively controlled by changing the voltage of electromagnet to maintain the air gap within an allowable range. The levitation force of an electromagnet is a non-linear function of current and air gap, and shows a saturation point beyond which it cannot increase when it reaches a high level. Therefore, a dynamics analysis of the Maglev vehicle that considers non-linear characteristics is needed to predict running stability. However, in preceding studies, the linear model, which may be obtained by using linear approximations of the levitation force for excursions around the nominal equilibrium point, has been used. In this paper, the relationship between the measured non-linear characteristics of levitation and guidance force and independent variables of current and air gap is processed by the interpolation method resulting 3-dimensional spline surface. By doing so, a non-linear levitation model was developed, and dynamic analysis was carried out. With the proposed model, the vertical and lateral air gap could be simulated to evaluate the running stability.