Abstract: The image of geometry and kinematics of fault and information for deep structural processes in 5.12 Wenchuan earthquake, occurred in the Longmen Shan thrust belt, the eastern margin of Qinghai-Tibetan Plateau, provide opportunities for understanding dynamic mechanisms and processes of formation of the Longmen Shan thrust belt. The fault coseismic displacement size, kinematics figuration and its spatial variation also provide an present example to test and check theory and methods of fault geometry, kinematics and dynamics analysis. This paper is intended to clarify the significances of fault co-seismic displacement in Wenchuan earthquake, discuss its kinematic models with consideration of earthquake dynamic force, regional tectonic stress field and possible deep tectonic process. Meanwhile the implications of the tectonic deformation phenomenon presented in Wenchuan earthquake for the theory and methods of fault structural anlysis is explored. The following preliminary suggestions are proposed on the basis of above analysis. Firstly, the co-seismic displacements determined by measuring the elevation contrast between two sides of the fault rupture surface is not entirely due to extending of deep structural displacement, but maybe partly due to differences of the intensity of the structural damage (expansion) of deep rock masses between the upper and down fault blocks along fault rupture surfaces under the earthquake dynamic impact forces. The gravity, wave velocity and electrical resistivity changes before and after the earthquake may also be indicative of the deep rock of the existence of structural damage. Secondly, seismogenic fault slip-thrust displacement and its spatial variation in Wenchuan earthquake could be interpreted by couple actions of regional tectonic stress and earthquakes dynamic impact forces, that is, the vertical displacement component can be attributed to south-east regional tectonic compression stress and earthquake dynamic impact forces that is nearly orthogonal to fault plane at the top of earthquake source body. This explanation could be supported by mainly taking thrusting in the south segment of Yingxiu-Beichuan fault and Pengguan-Jiangyou fault. While in the north eastern segment of Yingxiu-Beichuan fault, that is Wenchuan-Qingchuan segment, due to direction of earthquake dynamic impact forces not orthogonal to the fault plane, and the intersectional angle between them gradually decrease from south to north, even if the tectonic stress direction is still vertical to the fault, but the composite action of tectonic stress and earthquake dynamic force is bound to cause to the gradually increase of the strike-slip displacement component. The total displacement sizes of fault would be decrease with the increase of distance from the earthquake source body. Finally, the fault coseismic displacement scale and its spatial variation, especially different direction scratches on the same fault friction mirror in Wenchuan earthquake, provide opportunity to reverse the theory and principles of the geometry and kinematics of the fault. When we carry out research on faults underwent multiple deformation and activities, how to identify different deformation episodes and its kinematics, how to understand geometrical and kinematic changes along the fault and its relation to corresponding uniformly regional tectonic stress field uniformity, are really investigated.