The study aims to provide some plausible explanation for why Vietnamese listed companies only stop at the level of truthful presentation of information related to accounting data through the opinion of independent auditors. The information is only at the level of compliance with the requirements of Circular 155/2015/TT-BTC in form, but in essence is sketchy. What factors affect the level of voluntary disclosure of listed companies in Vietnam? In order to identify the factors affecting voluntary information disclosure on annual reports of listed companies, the study collected data on annual reports of 122 companies listed on the stock market in Ho Chi Minh City in the period 2015-2018 and uses regression analysis methods. The research presents 8 factors affecting the level of voluntary information disclosure including: Firm size, Listed time, Profitability, Solvency, Separation of board of directors and executive director, Board size, Organizational ownership and Foreign ownership. Next, the study conducted descriptive statistical analysis correlation coefficient analysis to examine the correlation and relevance of independent variables measured by the scale ratio, testing multiple linear regression model. The results of the study show that factors listed time, profitability and organizational ownership affecting voluntary information disclosure on annual reports of listed companies in Vietnam.

Abstract
1. Introduction
2. Literature Review
3. Research Methods
    3.1. Measurements
    3.2. Data
    3.3. Empirical Model
4. Research Results
    4.1. Descriptive Statistics
    4.2. Testing the Research Model
5. Results and Discussion
6. Conclusion
References

• Thi Mai Huong NGUYEN(Faculty of Accounting, Banking University of Ho Chi Minh City)
• Ngoc Tien NGUYEN(Faculty of Economics and Accounting, Quy Nhon University, Binh Dinh) Corresponding Author.
• Hong Thu NGUYEN(Thu Dau Mot University, Binh Duong)