This objective of this study is to enrich the literature by the debt ratio and enterprise performance of Joint stock companies of Vietnam National Coal and Mineral Industries Holding Corporation Limited (Vinacomin). The debt ratio is an important index of capital structure, and it influences and decides the enterprise performance. Therefore, the determination of reasonable debt ratio level is beneficial to the stable operation of Vinacomin’s enterprises. Based on the research conclusion about the effect on capital structure of debt ratio from domestic and foreign scholar, collecting data from 2014-2018 of Vinacomin’s enterprises as a research sample, the article conducts research on the relationship between debt ratio and business performance of Vinacomin, as measured by return on total Assets. In addition, the study uses free cash flow, company size , growth opportunity, investment opportunities, operating costs to sales ratio as control variables.The study shows the debt ratio of Joint stock companies of Vietnam National Coal and Mineral Industries Holding Corporation Limited has a negative effect on the enterprise performance. Furthermore, the research results of the article are references for Vinacomin’ enterprises in the course of production and business activities, determining a reasonable debt ratio, and improving the operational performance of enterprises.

Abstract
1. Introduction
2. The Relationship between Debt Ratio andEnterprise Performance
3. Research Methodology
    3.1. Research Data
    3.2. Research Model
4. Empirical Results
    4.1. Summary Statistics
    4.2. Choose the Model Estimation Method
    4.3. Regression Results
5. Conclusions
References

• Thi Thuy HOANG(Hanoi University of Mining and Geology) Corresponding Author
• Lien Thi HOANG(Hanoi University of Pharmacy)
• Thi KimThu PHI(Hanoi University of Mining and Geology)
• Minh Thu NGUYEN(Hanoi University of Mining and Geology)
• Minh Quang PHAN(Hanoi University of Mining and Geology)