Abstract: The dynamic and nonlinearity of the distillation column often become major constrain in selecting an appropriate control system in achieving the desired product purity. The aim of this research is to study the level of nonlinearity of the industrial i-Butane/n-Butane distillation column in order to propose a suitable controller. This will serve as a preliminary study in order to develop a robust controller for the column based on its degree of nonlinearity. In this study, the steady state model of the column is developed using commercial process simulator, Aspen Plus software and then validated with the industrial data available in the literature. Then, the model is exported to Aspen Dynamic and linked with Matlab Simulink for the dynamic study purpose. The nonlinearity analysis i.e. asymmetric response, harmonic response, input multiplicity and output multiplicity is done in order to study the nonlinearity level of the column. Based from the study, the industrial column under consideration can be categorized as a strong nonlinearity system and the development of a nonlinear controller is needed for the column.