Abstract: To discuss the technology of integration of heterogeneous information sources which can provide a unified interface to make use of various heterogeneous information sources for the information modernization of enterprises and applications based on Internet. It shields the heterogeneous information sources for users and applications. So it is easy to extract the needed information quickly. The integration technology of heterogeneous information sources is expanded from traditional structured databases to semi structured Web pages and non structured information. This paper analyzes the technical approaches of integrating heterogeneous information sources, such as data model, Web information, description laguage XML, main current of software development technology, information intelligent search, query rewrite and query analysis. Trends of development of this field are expected.