We propose a method to manage documents of engineering solution case based on TRIZ contradiction matrix theory. The document of engineering solution case involves know-how and techniques for solving mechanical issue. Usually the documents are written by engineers and practitioners, and managed by a company for sharing and inheriting among employees. However, an engineer who lacks literacy cannot find the previous case documents due to the inadequate keyword selections. To solve the query issue, we introduce TRIZ contradiction matrix theory for categorizing case documents. The engineers can retrieve adequate case documents by selecting improvement parameter and deterioration parameter on the matrix. Since the classification based on the matrix substantially categorize the case documents in terms of the problem solving methodology, it is effective and straightforward way of the specialized field and the key word. It is construction of the knowledge management support system that applies the idea of TRIZ. The problem solving that uses the reference information on this system is practiced and effectiveness is verified. © 2009 Springer Berlin Heidelberg.