Reactions commonly used in synthetic organic chemistry are named after their discoverers or developers. They are called the name reactions and generally consist of several elementary reactions. Quantum chemical calculations can optimize transition state (TS) structures of the elementary reactions. The geometrical feature of TS is called TS motif. We have constructed a database (QMRDB) with the TS motif information and have been continuing to accumulate them. In the present study, we extracted 102 elementary reactions from the QMRDB and attempted to classify them using the Kohonen self-organization map. As the results, all the TS motifs were clustered. By firing a target compound on a Kohonen map generated, we expect to be able to easily find the TS motifs most similar to the target.