1. An apparatus for processing information about a network including a plurality of nodes, wherein m attributes (m represents an integer of 2 or more) assignable to each of said nodes are defined depending on the relationship to another node which can be connected to said each of the nodes, said apparatus comprising: identifier generating means for converting attributes assigned to each of n nodes (n represents an integer of 3 or more) per relationship to the other node connected thereto into numerical values with respect to motifs extracted from said network as predetermined patterns of the connected relationship of then nodes, and generating identifiers identifying said motifs using said numerical values; and analyzing means for determining at least one of said motifs included in said network as an object to be analyzed based on said identifiers generated by said identifier generating means, performing a predetermined analyzing process on said object to be analyzed, and calculating the number of occurrences in said network of a corresponding motif with respect to each of said identifiers generated by said identifier generating means according to said analyzing process.