In this study, a molecular technology which allows for automated exploration of unknown elementally reaction processes systematically and applicable to a wide variety of chemical reactions will be developed. This is one of highly important subjects in quantum chemistry, and expected to break out the traditional paradigm for theoretical studies of reaction mechanisms which requires some guesses concerning the corresponding reaction mechanism in an analysis of a reaction mechanism. Moreover, this technology, once established, will open the way for automated exploration of unknown chemical world by computers. In this project, we will establish such a molecular technology by expanding applicability of automated reaction path search methods which have been developed by ourselves and applied to simple systems.