This study examined the effect of interpersonal character strength of service employees on their emotional aspect of happiness. Interpersonal character strength has been shown to be a critical skillset required for service encounter employees, thus is expected to increase the levels of employee happiness, as well as to moderate the relationship between emotional labor strategies (e.g. deep acting and surface acting) that employees useand their positive emotion. The results from a sample of 129 receptionists working at imported electronics show rooms and service centers showed that interpersonal character strength indeed had a significant positive effecton happiness, even after controlling demographic variables and other character strengths. Furthermore, interpersonal character strength moderated the relationship between deep acting and happiness so that emotional laborers with high interpersonal character strength experienced more positive emotion when using deep acting strategy, as compared to those with low interpersonal character strength. These findings offer suggestions for organizations and their employees to develop both deep acting strategy and interpersonal character strength in order to enhance the level of happiness of employees.