Abstract: Based on the micro-structure of materials in a tire,a 3D analysis model is presented in this paper.Geometrically nonlinear behavior resulted from large displacement,physically nonlinear behavior and bi-modulus of materials of various parts of the tire are considered.For changeable contact field with road,a parameter is used to improve the accuracy of hypothetical contact field.The incandescent Light Spectra Technique is used to measuer the surface displacement field of the tire,a comparison of theoretical and experimental results show a good agreement.