Continuous Traffic Flow Dependency Analysis of Urban Periphery Freeway Consecutive Section base on Principle Component Analysis Urban periphery road network is a special type of roadwork pattern that scatters and distributes around the specific zone of metropolitan and in that contains different grade and functional roads of arterial road, urban freeway and expressway. Urban traffic flow and inter-cities flow transform and divert intensively and massively in this zone also traffic jams and incidents frequently in this zone. Traffic control is necessary and the first basic sector of various different roads should be clearly. In this paper, from the characteristics analysis of continuous traffic flow, utilized the data mining idea and method, the principle component (PCA) was applied to analyzing the dependency of different types of road section that concluded in junction road network. Took Beijing city junction road network as case study, through the analysis of continuous historic data of traffic flow of urban freeway and inter-cities expressway in junction road network, the dependency and their comparison were obtained independently. As a result, the research can benefit reference for macro traffic flow control and guidance.