Some spread footings of real engineering practices of bridges in Taiwan were found to be uneconomically large due to the restriction of foundation uplift regulated in design code. Although the rocking mode of spread footings induced from foundation uplift is not acceptable in general and not taken into account in analysis, some researchers have indicated that rocking itself can act as a form of isolation mechanism. Uplift of foundation can limit the earthquake forces transmitted to column base, hence to decrease the plastic deformation occurring at the plastic zone. Besides, unless very massive footing, some uplift on the tension edge of spread footing during a major earthquake is not avoidable. Thus, analyses based on the assumption that the foundation and soil are firmly bonded would not only lead to unreasonable large internal forces in columns, sometimes it would also underestimate the disadvantage that may be brought by rocking, such as large lateral displacements at the deck and permanent settlement in soils. In this regards, to realistically consider the effects of the interaction between the foundation, column and soil becomes an important issue. In order to gain better understanding of rocking mechanism and consequently to have more confidence in taking its benefit into consideration for design, an analytical model which can consider the nonlinear interaction between column, foundation and the underlying soil was established using Sap2000N. This analytical model was validated through the comparison with the experimental data. Using this analytical model, an extensive parametric study was performed and the influence of foundation size, soil stiffness and soil ultimate bearing capacity on rocking behavior was calculated.