Economy linkages and their structure inter cities within a province provides the basis for the fusion and interaction development of regional economy. Adopting the information of key enterprises on city-level and industrial linkage on province-level, we obtain the input-output relationship between cities and calculate the economy linkage weight. Base on this, we correct in gravitational model which was used by Wang Xin et al to measure the strength of economic ties inter cities. After comprehensive considering the impact of such factors as industrial structure, enterprise activity, economy gross, space distance and urban population on the economic linkage inter cities, we build city network model within a province which can objectively reflect the structure of economic relations inter cities. Then the data of Shandong province is used for case analysis. Through analyzing four kinds of structures of Shandong city network, we measure some influence of each city according such items as the impact of one city on other direct-related cities, the status of one city in the urban agglomeration, the control and coordinate ability of one city to the urban agglomeration, the potential impact of one city and so on. The study results provide ideas of economic integration and interactive development inter cities within a province for the perspective of economic connection.