Abstract
This research is based on the problem of the existing phenomenon that many companies have poor corporate governance therefore the practice of tax avoidance has increased and there have been chances in earnings management. In addition. there is a lack of research in Indonesia looking at the information of tax avoidance associated with earnings management by taking into mechanism of corporate governance which is inconsistency, it can be taken into consideration for researcher.

The aim of this research is to analyse the case of tax avoidance, earnings management, the mechanism of corporate governance measured by the Board of commissioners, independent commissioner and the institutional ownership influenching and their impact to value of the firm. This study investigated how the tax avoidance and earnings management as a basis of management has an effect to value of the firm. The study also tested indirect relationship between the ability of corporate governance mechanism has an effect on value of the firm with the tax avoidance and earnings management as an intervening variable.

Population in this study are all companies in manufacture industry has been listed in the Indonesian Stock Exchange from 2012 to 2016. The total samples were 87 companies with method of this research are using analysis of causality 10 find correlation and influences between variables.
The results showed that the corporate governance mechanism negative influences to tax avoidance and earning management meanwhile, the corporate governance mechanism has positive influence to the value of the firm. The other hypothesis has finding that the tax avoidance have positive influence to the value of the firm, otherwise the earning management have significancy with negative influence to the value of the firm. This research proved for indirect influences that corporate governance to the value of the firm with avoidance as mediate variable and show negative significancy to the value of the firm and if earnings management as mediate variable then the finding also show positive significancy to value of the firm.

Keywords: tax avoidance, tax loopholes, effective tax rate, earnings management, discretionary accrual, value of the firm, tobins’q, mechanism of corporate governance boards of commissioner, independent commissioners, institusional ownership.