The objective of the study is to analyze the effect of choice set on the estimation of non-IIA discrete choice models for two choice situation of railway route choice and day-return recreational destination choice model. Firstly, The day-return recreational destination choice model for non-IIA choice model is formulated using the idea of two elements of similarity. Secondary, we succeed to estimate multinomial probit model and mixed logit model for choice set with 10 alternatives. Finally, the effect of choice set on the estimation is deeply considered using actual and imaginary datasets.