A number of existing information retrieval systems propose the notion of query context to combine the knowledge of query and user into retrieval to reveal the most exact description of user's information needs. In this paper we interpret query context as a document consisting of sentences related to the current query. This kind of query context is used to re-estimate the relevance probabilities of top-ranked documents and then re-rank top-ranked documents. The experiments show that the proposed contextbased approach for information retrieval can greatly improved relevance of search results. Categories and Subject Descriptors H.3.3 [Information Storage and Retrieval]: Information Search and Retrieval ? Retrieval models. General Terms Algorithms, Design, Performance, Experimentation Keywords Query context, information retrieval, document re-ranking.