With the rapid expansion of web information, conventional information retrieval techniques are becoming inadequate for users and often result in disappointment, because a couple of simple keywords can easily produce information too much. This study aims at the development of Web information retrieval techniques based on semantics to improve the quality of understanding for information. To achieve the goal, this study analyzes technologies and current status of researches on semantic information retrieval. With the results which are requirements, system architecture and indexing method, this study proposes the system architecture of semantic-based information retrieval system.