Abstract: To satisfy the demand of different traffic modes to different grade roads, the urban road grade proportion is researched based on the equilibrium between the supply and the demand.The travel sequence related to across grade is discussed according to the discrepancy in function of each grade road and the preponderant trip distance on each grade road of all traffic modes is calculated under different travel sequences.The road transportation turnover on each grade road is considered as demand and the capacity as supply.Further, the length of each road grade can be obtained satisfying different traffic modes demands.Finally, with an example, a reasonable road grade proportion can be obtained.