The assumption about travelers’choice behavior has a major influence on traffic assignment． Cumulative prospect theory ( CPT) proposes an alternative framework to the traditional risk-taking modeling in route choice behavior，which might be more complicated but more scientific． Based on the choice framework of CPT，this paper establishes a link between the network stochasticity and traveler’s route choice behavior by calculating CPT-based commute utility． Moreover，we establish the CPT-based user equilibrium ( UE) model as well as its equivalent variational inequality ( VI) expression． Accordingly，an algorithm on the basis of the method of successive average ( MSA) is proposed to solve the UE model． Both the model and the solution algorithm are demonstrated in a numerical example． Sensitivity analysis of parameters involved is also dis-cussed in detail，which displays the effect of traveler’s risk preference，traveler’s expectation on network service level and network uncertainty on the UE flow distribution．