Abstract: Taking the expressway between Shenyang and Dalian as an example, the authors analyse the spatial competition system of expressway passenger flow. Based on the analysis of main conditions such as direct and indirect hinterland which influence the passenger flow, the atuthors probe mainly into the influence of the distribution of passenger railway stations between Changchun and Dalian which run parallel with the Sen-Da (Shenyang-Dalian) expressway on the formation of expressway, and the flow-division relation between expressway and railway which is restricted by such factors as traffic speed, ticket price and comfort degree, etc. Finally, the authors suggest that passenger administrative department coordinate the unity and opposites relation between the traffic operation department and passengers in respect of quantity, quality and beneficial result, etc, and by which increase the spatial competitive ability of expressway passenger traffic.