Research on employee commitment to the organization is necessary for human resource management, and the result is applied in practice to improve organizational effectiveness. The aim of the present study is to explore factors affecting organizational commitment at the small and medium-sized enterprises (SMEs) in Vietnam. Besides, the relationship between organizational commitment and job performance is examined as well. The research was conducted on a sample consisting of 67 white-collar workers and 260 blue-collar workers at SMEs. A total of 327 valid complete questionnaires were input into SPSS 20 database for processing to provide evidence. The research model and hypotheses were tested using the technique of the hierarchical multiple regression analysis. The research results revealed that income, reward and welfare, direct manager, working environment, coworker, and promotion opportunity tended to associate positively with organizational commitment. Besides, the finding also showed that, when the employee has a high organizational commitment, it would lead to high job performance. The main findings of this study provided some managerial implications for SMEs, in general, and managers, in particular. It implies that Vietnam’s small and medium-sized enterprises should improve these six factors to retain employees as well as enhance their job performance.

Abstract
1. Introduction
2. Literature Review
    2.1. Organizational Commitment
    2.2. Job Performance
3. Hypotheses Development
    3.1. Income
    3.2. Reward and Welfare
    3.3. Working Environment
    3.4. Coworker
    3.5. Direct Manager
    3.6. Promotion Opportunity
    3.7. Organizational Commitment and JobPerformance
4. Research Results
    4.1. Data Description
    4.2. The Reliability and Validity of the Scale
    4.3. Hypothesis Testing
5. Conclusion and Recommendations
    5.1. Conclusion
    5.2. Recommendations
6. Limitations of the Research
References

• Bui Nhat VUONG(Faculty of Labor Relations and Trade Unions, Ton Duc Thang University) Corresponding Author.
• Dao Duy TUNG(Faculty of Business Administration, Tay Do University)
• Nguyen Dinh HOA(Dean, Faculty of Labor Relations and Trade Unions, Ton Duc Thang University)
• Nguyen Thi Ngoc CHAU(Deputy Branch Director, HungCa company)
• Hasanuzzaman TUSHAR(College of Business Administration, International University of Business Agriculture and Technology)