The purposes of this research were :1) to study the problems and needs of the customers about behavior of service personnel in Nong Song Hong Hospital, 2) to study the satisfaction of patients in Nong Song Hong Hospital, 3) to study the development of service behaviors of participant personnel in Nong Song Hong Hospital, 4) to compare the knowledge gained from personnel knowledge about service behavior before and after the training and 5) to study the development of service behavior of Nong Song Hong Hospital personnel. The research methodology was action research. The sampling were 52 personnel working in the outpatient department. Collecting data by questionnaire, semi-structured interview, knowledge test group, observation, focus group and AIC techniques. Phase 1-Study of problems and needs of customers .Phase II- Study of the development of service behaviors of personnel with AIC technique, during June 2018 - October 2018. Data were analyzed by descriptive statistics and analyzed by qualitative data by content analysis. The search results : 1) The problems and needs were : that some of Staff were not ready to serve, lack of enthusiasm, communication, emotional control skills, Customers need service mind, good communication skills, and humanize care, 2) The satisfaction of the service recipients was at the moderate level, considering the aspects were, courtesy was at the much and the responsibility, sympathy, tolerance, emotional control were at the moderate level and the communication. 3) The results of participatory behavioral development from observation of personnel participation and cooperation in the activities were very good. The knowledge gained after the training increased significantly (p =.01). The result of the development found that the staff have changed their behavior in a better way, such as being ready for service, smiling, greeting the recipient. Finally that the development of service behaviors of personnel appropriate to the context of Nong Song Hong Hospital. Service recipients are more impressed with the service.