Computational mechanics are based on numerical methods and high-performance computers while artificial intelligence (AI) tools are based on knowledgebases. A new concept on structural analysis by using AI technique is presented in this paper. A fully artificial intelligence approach has some significant meanings: 1) The field of computational mechanics should include problems which shows very complicated phenomenal behavior, but have low degree of freedom. 2) An approach supporting the conceptual design stage of structures should provide a very flexible simulation capability of structural behavior. Artificial intelligence tools will provide some solutions to these. The purpose of this research is to investigate the benefits derived from the application of an artificial intelligence approach to structural analysis fields. A prototype knowledge-based system, called OOTA (Object-Oriented Truss Analysis), is developed to analyze me truss structures. Since the system does not use any numerical method, the computation requires much time. But, it provides many advantages for small but complex problems including material and geometric nonlinearlities.