Human-induced excitations are the most important source of vibration for footbridges. The dynamic analysis using mathematical time-domain force models cannot consider the dynamic effects of the mechanical human body and the human-structure interaction. In this study, the mechanical human body model generating pedestrian excitation is developed to analyze the dynamic behaviors of footbridges considering the interactions between bridge and human bodies walking through the footbridges. The dynamic behaviors of the footbridge by the analytic method using the developed human body model are compared with dynamic behaviors of the footbridge by the analytic method using the force model and by the experimental method. In conclusion, the developed human body model are simulated the people walking in crowds effectively.