Abstract: Risk produced by uncertatinty is an inherent feature of traffic system, so by a survey of personal socioeconomic character, traffic conditions and psychology expriment, mechanism and characteristics of risk preference in commuters’ route choice behavior were studied. Considering the definition of risk preference in accordance with prospect theory, risk aversion and risk seeking were researched in gain domain and loss domain respectively with linear discriminant analysis. Result shows that risk preference in gain domain and loss domain are quite different. In the gain domain commuters are more likely to be risk aversion, which is related to the personal socioeconomic characters.