The purpose of this study is to investigate the impact of narcissism on employees’ social media addiction and how it influences their job satisfaction and organizational commitment. And this study explores if perceived organizational support can moderate the relationship between narcissism and social media addiction. For this, this study collected data from 285 employees in Korean companies through a survey method and uses SPSS 18.0 for hierarchical regression analysis in the hypothesis test. First, organizational politics increases mood modification, withdrawal and tolerance among the sub-factors of social media addiction. Second, each phenomena of social media service addiction such as salience, withdrawal and tolerance decrease each relevant factors of job satisfaction and organizational commitment. Third, withdrawal and tolerance among the sub-factors of social media addiction play the mediating roles between narcissism and each relevant factors of job satisfaction/organizational commitment. Finally, perceived organizational support decrease the effect of narcissism on mood modification, withdrawal and tolerance among the sub-factors of social media addiction. This study provides some of managerial implications to corporate executives who try to manage organizational attitudes.

Abstract
 1. Introduction
 2. Literature Review and HypothesisDevelopment
  2.1. Antecedents
  2.2. Consequences
  2.3. Mediating effect
  2.4. Moderator
 3. Methodology
  3.1. Data collection and sample
 4. Results
  4.1. Relationship between variables
  4.2. Hypothesis Test
 5. Conclusion
  5.1. Discussion
  5.2. Limitations and future research directions
 References

• Youngkeun Choi(Associate Professor, Division of Business Administration, College of Business, Sangmyung University)