Abstract: The tendency of city economic growth and the development of industrial structure contains the process of market relationship conversion and the value flow shift between sectors of national economy. Each sector requires others’ outputs as production factors， meanwhile provides its outputs to other sectors as consumption. And then there exists interdependency and interaction of demand-supply relationship between sectors. This kind of complex relationship structure is similar to certain industrial network. Network analysis of the industrial structure is an important aspect in study area. The present studies focused primarily on two aspects： the determination of the network topology indicators. These analyses have a common characteristic： the vast majority of them are tending to explain industrial network as topology network. But they missed the point that the discussion of network nodes and rims’ actual significance. In this regard，there are three aspects worth to be analyzed. First，it is not meaningful to measure the connectivity of industrial network by average shortest path. Second，undirected treatment and unweighted treatment can’t reveal the true face of the industry network. Third，most of the studies did not carry out the discussion on self-loop. As an open and dynamic system，inter-industry relation in industrial network affects the development state of various industries，and in turn drives the evolution of industry network. For this reason，it is very necessary to find out the topology characteristics of industry network and figure out the evolution process of industry network. On the basis of the analysis of strengthen the weight of rim and node，in consideration of the random walk centrality， this paper attempts to answer two specific questions. First，what changes have occurred on industries’ position in network structure? Second，whether the network centralities rank of industries change significantly? If there are any change，dose this change reflects the direction of Beijing industrial restructuring?On the basis of the input-output tables of Beijing in 2002 and 2007，this paper constructs the industrial network of Beijing， and analyzes the evolution of the network features， then discusses the changing transaction status of sector nodes from 2002 to 2007. The results are as follows：（1）During the 5 years，following the network’s trading pairs of sectors increasing，the transactions have become more aggressive to promote the network and the network accessibility. （2）for transaction scale，the changes of trading centers’ status are different in 2002 and 2007，and the network structure roles of demand-supply center are also different. （3）there is a obvious change in the distribution of number of the trading markets， and the increasing rate of trading market number of tertiary industry is higher than secondary industry. It shows the trends of upgrading in industrial structure. （4）the strength of transaction linkage and the differences of sector trading have been expanded. However，the object of first trading sector is relatively stable，and the feature of self-loop trading is prominent. （5）the change in rank of sensitivity of tertiary industry and secondary industry is different，but the random walk centrality of producer services industry is steady.

Key words: industrial network, centrality, random walk centrality, input-output, Beijing