Compare with the general road, expressway have a clear differential benefit, the causes of Road users to choose the expressway from its time-saving, cost-saving and comfort. With the abolition of the general level roads charges, the differential benefit of the expressway significantly turn lower. Therefore, it is need to evaluate the rate of the expressway toll rate, To investigate whether the existing toll rate under the new situation could maximum economic benefits and social benefits of expressway. In this paper, by analyzing the factors which impact the expressway toll rate, proposed a method to evaluate the reasonableness of expressway toll rate, and give an example to illustrate.