Independence is a factor which has a significant impact on auditing quality, especially in the recent times where the marketplace is increasingly demanding transparency. The independence of auditors is assessed based on the main criteria such as the reliability of the audit opinions, the accuracy, truthfulness of financial reports, and the objectivity in the opinions of the auditor. The study investigates the effects of non-audit services (NAS) on auditor independence in emerging economies such as Vietnam. Non-audit services include taxation services, management advisory services and outsourcing internal audit services. Based on previously relevant researches, the authors develop hypotheses and a regression model about non-audit services (independent variables) and audit independence (dependent variable). The research collects data by 5-scale Likert questionnaire. The findings indicate the relationship between NAS and auditor independence. Specifically, the results reveal two main factors that have influence on auditor independence, namely, taxation services and management advisory services. The results of our research can be considered as new findings and can be compared to previous researches in Vietnam, which establishes a new viewpoint about the relationship between the NAS and the independence of the auditor. This result can be implemented for countries or jurisdictions which are similar to Vietnam.

Abstract
1. Introduction
2. Literature Review and Hypotheses
    2.1. Auditor Independence
    2.2. Non-Audit Services
    2.3. The Effect of Non-Audit Services (NAS) onAuditor Independence
3. Methodology
    3.1. Research model
    3.2. Data Collection
4. Research Results
    4.1. Descriptive Statistics
    4.2. Cronbach’s Alpha Test of Scales
    4.3. Exploratory Factor Analysis
    4.4. Pearson Correlation Analysis
    4.5. Regression Analysis
5. Discussion
6. Conclusion
References

• Nga Thanh DOAN(Department, School of Accounting and Auditing, National Economics University, Vietnam.)
• Cuong Duc PHAM(Head of Accounting Principles Department, School of Accounting and Auditing, National Economics University, Vietnam) Corresponding Author
• Thuong Thi Uyen NGUYEN(School of Accounting and Auditing, National Economics University, Vietnam)
• Mai Phuong VU(School of Accounting and Auditing, National Economics University, Vietnam)
• Lam Ha PHAM(School of Accounting and Auditing, National Economics University, Vietnam)