A community is extracted by executing steps of: clustering relationship data; extracting a communication core of a relationship network; mapping the communication core to a dendrogram of relationship data; forming a community by using the dendrogram in accordance with a similarity degree of relationship data while the cluster is expanded; and aggregating communities. A community of a set of persons having high density relationships based on common topics and interests can be extracted from a set of human relationships and relationship data representative of the human relationships.
Method of extracting community and system for the same