The machining accuracy and reliability of anti-resonance of machining center were largely affected by the dynamic characteristic of longitudinal feeding system in Z-direction of vertical machining center. The dynamic characteristic of longitudinal feeding system in Z-direction of vertical machining center was analyzed by using the Finite Element Method (FEM), and the research on the way of dynamic FEM modeling of the feeding system which integrated with the joint surface characteristics was conducted. By modal analysis and diapason response analysis, the free frequency and vibratory characteristic of the feeding system were gotten, and the correctness of FEM result was proved by experiment. Thus the analysis results provide the dependable basis for the intelligent selecting of milling parameters and increasing of dynamic performance of the machining center.