Background/Objectives: In order to derive foam model's parameters for simulation, steady state experiments should be conducted because it can satisfied local equilibrium condition for modeling. Although this method is commonly used, it is time-consuming. Unsteady state experiment is one of the alternative approaches. In order to utilize this approach, it is required to be proven whether can satisfy local equilibrium or not. Analysis: In this study, the condition of local equilibrium in unsteady state experiment was investigated. All governing equations in foam process were utilized to show whether in unsteady state experiments there is local equilibrium or not. In order to achieve the goal of this study, Various Assumptions were considered to simplify the model. Finding: As results, it has been proven that the local equilibrium condition can be applied to the front zone in unsteady state foam flooding. Regarding this result, it can be concluded that to drive model parameters of foam assisted process, unsteady state experiments can be performed instead of the steady state. Novelty: Accordingly, this study aims to prove that whether the unsteady state data can be utilized to in foam modeling or not.