Web Index (WIX) is a hyperlink generation system that achieves joining information resources on the web. The WIX system takes a set of pairs of keywords and URLs written in XML (called WIX Files) and join it to the text content of a web page in order to transform keywords into hyperlinks to a specific web page group of the user's choice. In the previous WIX system, synonymous expressions of the same entity had to be directly added to the WIX File in order to generate hyperlinks for such expressions. In this paper, we propose a synonym processing mechanism, which generates the hyperlink for synonyms without adding them to the WIX File directly. We collected synonymous relations from the redirection function of the Japanese version of Wikipedia and constructed a synonym database for our system. We incorporated the information of the Synonym database into the automaton based on the Aho-Corasick algorithm used for the lexicographic matching process of the WIX system, and achieved to generate hyperlinks on synonymous expressions without barely changing the size of our WIX File database.