This study is conducted with the aim of explaining the role of extraversion on employee loyalty with the mediating role of career and social adaptability among employees in a private organization. The research design is descriptive-correlational and the population is the employees of Saveh Chocolate Factory up to 240 people. According to Cochran's formula, the sample size of eligible people in this study is 172 subjects chosen randomly. The research data is collected by questionnaires of extraversion, social adaptability, occupational adaptability, and employee loyalty collected each of which has acceptable reliability and validity to study the mentioned variables. Pearson correlation and SPSS software are used to analyze the data. According to the Pearson correlation coefficient, the obtained results suggest that the relationship between extraversion and employee loyalty (ρ= -0.564) is a significant inverse relationship, and the relationship between social and occupational adaptability with employee loyalty (ρ =0.431, ρ =0.579) is a direct and meaningful relationship. Moreover, according to the results, the direct significant relationship between extraversion and social adaptability (ρ=0.453), extraversion and occupational adaptability (ρ=0.297), and occupational adaptability with social adaptability (ρ=0.487) are approved. The findings besides confirming the existence of a significant relationship between extraversion, social and occupational adaptability with employee loyalty show that each of the mentioned behavioral characteristics are associated with each other, and explain the quality of this relationship to be used for better analysis of the employee loyalty in organization. Manuscript profile