Abstract-Near field acoustic levitation (NFAL) has been used in non-contact handling and transportation. The levitation force is generated by the squeeze film. In order to descript the levitation force precisely, we built a mathematic model of the squeeze film, considering the gas inertia and relevant nonlinear effect with high frequency oscillation. Finite element method (FEM) simulation and measurement test are used to obtain the distribution of squeeze film pressure. Results show that the gas inertia has a significant influence on pressure distribution. The predicted levitation force also agrees with our experimental measurements. This study presents the gas pressure distribution with different mode shapes and explains the mechanism of the NFAL.