On the basis of consumer surplus theory, the idea that transportation supply quality and price should be decided on the premise of demanders' benefits is put forward. Hence, a measurement model for transportation demand economic cost is established, and qualitative analysis for the structural factors of the model and its influent as on the consumers' economic cost is conducted. The analysis shows that the actual influence of transportation price on both suppliers and demanders is dissymmetrical. Because of this, it is not good to analyze the supply-demand balance laws from the view point of prices. The fact is that the higher the value of transportation goods, the smaller the influence on transportation economic cost in its transporting process.