Abstract: Question Answering System (QA) allows users to ask question in natural language. Using natural language processing technology, QA returns answer to the user automatically. I}he paper used WordNet to construct lexical chains, and used the lexical chain in a ctuestion answering system based on the Internet. Using two kinds of different way calculates similarity of Snippets download from Google to sort them according to similarity. When going for the first one and first ten Snippets, the accuracy of the answer snippets is increased by 13. 68 0 o and 25. 4 0 o. We made significant inspection for the experiment results. In significant level scheffe post hoc 0. 05 conditions, p=0. 000078 is got and the accuracy of the system is dramatically improved.

Key words: WordNet, Lexical chains, Question answering system