In this paper, we propose a framework for searching information through both the WWW and a human group. Though information retrieval using a searc engine in the WWW is very useful, we can not acquire local information owned by persons and not explicitly described in text. A user knows neither where target information is in the WWW nor who knows in a human group. Thus we integrate the information retrieval in the WWW with that in a human group, develop a heterogeneous information search system HERIS as a multi-agent system. We develop this framework as multi-agent system consisting of user agents and search engine agents, and use contract net protocol to communication among the agents. A user agent and a search engine agent are assigned to a user and a search engine. Each of the agents maintains a user profile and a search engine profile. When a user gives a query to a system, it selectively searches information resources consisting the WWW and user group. Finally a user acquires integrated results of a hit list from the WWW and a audio/video connection to a user who can answer the query. It was found through experimental evaluation that information retrieval using a human group as an information resource is valid and a search with HERIS has a different character from conventional search engines.