Background: With increasing computerization of nursing records in Japan, standardization of nursing terminology is becoming imperative. Although some efforts have been made to formalize description of nursing practice in Japan with the International Classification of Nursing Practice (ICNP®), lack of effective descriptive tools has impacted negatively on the initiatives. Our hypothesis is that the description of nursing actions in Nursing Master with the ICNP® would probably produce a knowledge base of dissection that can also be used as an intermediate representation for a semi-automatic translation into a formal model. Purpose: To develop and evaluate an ontological approach that could be used to facilitate the description of nursing practice in Japan with the ICNP®. Methodology: An ontology-based support system is developed using Protégé-2000, mainly by the following three steps: 1) representing a standard classification of nursing practice (Nursing Master) in Japan; 2) representing a Japanese version of the ICNP®; 3) designing an ontology-based framework. A heuristic matching algorithm is developed to automatically match the action labels in Nursing Master with the terms of the eight axes of the ICNP® Nursing Actions Classification, providing the domain experts the knowledge for the purpose of description support. Final Report: Jiang, G., Sato, H., Endoh, A., Ogasawara, K., & Sakurai, T. (2007). An ontological approach to support the description of nursing practice in Japan with the ICNP. International Journal of Medical Informatics 76, 55-65.