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.