The purpose of this study is to clarify the competencies used by public health nurses in creating new health care systems in the community. The subjects were four public health nurses who were nominated by other public health nurses. As a method a qualitative method was used. Each subject was interviewed using a semistructured questionnaire which was made based on each system she had developed. Each interview was tape recorded and transcribed verbatim. Data were analyzed and divided by the seven domains proposed by Benner. The results showed that public health nurses took roles in six out of the seven domains of Benner. Among them the "Organizational and Work-Role Competencies" domain had a lot of content and was divided into more detailed seven subcategories. All four public health nurses were stimulated to create a new care system by exposure to a serious case and being moved deeply through visits to homes and hospital. The desire to solve the problem of individual clients leads to the establishment a new system in the community, showing the originality of the role of public health nurses who have nursing knowledge and who work in a regional government. In the process of building a health care system each public health nurse secured the budget or created a new measure of the regional government. It shows the significance of the role that public health nurses play in the regional government.