The study aims to verify the relationship between leaders’ personality traits in leader - member exchange (LMX), and job performance. Hierarchical Regression Analysis was used to examines (a) how leaders’ personality traits and LMX affect the influence of social capital on job performance and organizational citizenship behavior; (b) how perceived organization support (POS) can moderate the influences of LMX on social capital, in turn impacting job performance and OCB. Responses are employees in the service industry in Thailand, which consisted of 236 independent samples in 77 groups. Each group included at least one leader and 1-5 followers. The results show that there is a significant relationship between leader’s personality traits, LMX and social capital. Leader with the higher level of conscientious, and agreeableness can always create good relations with their followers. The level of LMX are also related to social capital and both of these influence OCB and job performance. The moderating effect of perceived organizational support is also significant that POS can amplify the influence of LMX on social capital. Finally, the research findings show that perceived organizational support is one of the moderating factors in LMX exchanges. Followers perceived organizational support can amplify the influence of LMX on social capital.

Abstract
 1. Research Background and Motivation
 2. Literature Review
    2.1. The Relationship between Follower and Leaders’ Personality Traits and LMX
    2.2. The Relationship between Leader Member Exchange (LMX) and Social Capital (SC)
    2.3. The Relationship between Social capital(SC) and Job Performance (JP)
    2.4. The Relationship between Social Capital(SC) and Organizational Citizenship Behavior
    2.5. The Relationship between Perceived Organizational Support (POS), Leader Member Exchange (LMX) and Social Capital (SC)
 3. Research Design and Methodology
    3.1. The Conceptual Framework
    3.2. Questionnaire Design and Construct Measurement
    3.3. Sampling Plan and Data Collection Procedure
 4. Research Results and Discussions
    4.1. Descriptive Analysis
    4.2. Confirmatory Factor Analysis (CFA)
    4.3. Hierarchical Regression Analysis
 5. Conclusion and Suggestions
    5.1. Research Conclusions
    5.2. Research Implication and Contributions
    5.3. Research Limitation
 References

• Duc-Thuan TRAN(Faculty of Economics-Management, Dong Nai Technology University)
• Li-Yueh LEE(Department of Business Administration, Kun Shan University)
• Phuoc-Thien NGUYEN(Department of Business Administration, Nanhua University) Corresponding Author
• Wethima SRISITTIRATKUL(Department of Business Administration, National Cheng Kung University)