The purposes of this study were to study 1) personal factors affecting Rajamangala University of Technology Phra Nakhon (RMUTP) personnel’s happiness at work 2) personal factors affecting the personne’s l work ethics and 3) relationship between the ‘s personnel happiness and ethical behavior at work. 303 samples were selected using the Taro Yamane method. A questionnaire was applied as the instrument used for data collection. Statistics used for social sciences included frequency percentage mean standard deviation t-test and one-way ANOVA. The study indicated that 1. Personal factors were highly related to RMUTP personnel’s happiness at work either in the individual aspect or in the overall. 2. Personal factors were highly related to RMUTP personnel’s work ethics behavior either in the overall or in the individual aspect. 3. Happiness at work was related to RMUTP personnel’s work ethics behavior and resulted in ethical behavior of the university personnel with an average of 65.6%.