Extensive studies on the attitudes of the employees in the organization have been conducted in that it influences on the outcome of the organization, and companies continuously seek to enhance organizational commitment and organization citizenship behavior by improving individual variables. Especially clerical employees working in large company with relatively high employability are changing from lifelong commitment in one organization to recurring short-term commitments where individual potentials can be realized based on their movable networks. Therefore, it is important to examine factors that contribute to organization citizenship behavior, the main variable, for enhancing organization commitment and organizational effectiveness which have been studied as important topics for improvement of organizational outcome and retention of employees in large company. Although a number of previous studies revealed the influence of calling on organizational commitment and organization citizenship behavior, studies with social support from members’ interpersonal relationship in the organization as a moderator variable were limited. Thus, the purpose of this study is to examine the influence of calling on organization commitment and organization citizenship behavior of employees working in a large company in Korea and to present the measures that can enhance organizational commitment and organizational citizenship behavior by verifying the moderating effect of social support from the interpersonal relationship. The result of the study suggests calling of employees working in a large company is a significant influence on organizational commitment and organizational citizenship behavior. In addition, the moderating effect of social support in the relationship between calling and organization commitment, and between calling and organization citizenship behavior was verified to be positively valid respectively. Practical implications are suggested to influence organizational commitment and organizational citizenship behavior through enhancement of calling of employees and social support.