The purpose of this study was to develop the nursing information system based on the Standardized Nursing Language System for gastric cancer patients according to the framework of the nursing process. This study also tried to evaluate the usability by applying it to the gastric cancer nursing practice. The system was developed based on the System Development Life Cycle. Therefore, it is considered that the gastric cancer nursing information system developed in this study can contribute to the improvement of clinical usability under the nursing process and to the enlargement of the range of nursing records. In addition, the system developed in this study was based on the Standardized Nursing Language System, for effectively controlling data related to gastric cancer nursing. The gastric cancer nursing information system in this study can be applied effectively in the quality control of nursing care, follow-up care and research for the whole nursing field as well as in cancer nursing, and can promote the use of the Standardized Nursing Language System.