Rocking and uplifting of shallow foundation bridge pier during earthquake is known to act as a form of isolation mechanism, potentially reducing the internal moment of the column and possibly protecting the column from damage. However, spread footing foundations of bridges in Taiwan are designed to be fixed to the ground even during earthquake. This insistence of not considering the effect of rocking underestimates the advantages that might be brought by it. In order to use rocking concept with more confidence in practice and to be applied in codes and provisions, a more accurate prediction of how the structure will behave under seismic load is required. The goal of this thesis is to construct a numerical model representing an experiment program that had been conducted at NCREE and verifies the results obtained from the analysis with experimental result. By using the established model, parametrical analyses are performed to give better understanding of the subject. Additionally, a displacement prediction method of rocking system will be proposed. In spite of the presence of inaccuracy in the analysis, the models are able to capture the behavior of rocking and are able to generate a reasonable displacement response history, moment-rotation relation of the column and force-displacement relation of the structure. It is observed that smaller foundation size and higher longitudinal reinforcement bar will increase the possibility of rocking to occur, thus gives better protection to the column.