Abstract: This paper made use of Beijing's input-output direct consumption coefficient from 2002 to 2012 to build a sort of weighted undirected networks which were named Industrial Need-Competition Network based on co-citation algorithm. Then edge weight,unit weight and disparity in the weight were chosen to analyze competition relationship contained in the whole network. As results,edge weight reflects the extent to improve the industrial chain links,unit weight reflects the role in promoting industrial system,and disparity in the weight can be used to distinguish backward industries needing policy guidance from governments.