Understanding Good Faith Princıple And Applying Corporate Governance Principles Under Turkish Commer Kitap Açıklaması The 21th Century has experienced speedy development in the business area, so that new concepts and institutions were created by business requirements. Corporate governance principles appeared that consider stakeholder expectation and keep their trust. Moreover, corporate governance principles have three approaches, which are business, finance and law perspective. Regulations provide enforcement effects for applying new concepts but some resistance can appear amongst the implementers.The present research focused on the law effects on corporate governance principles between listed companies and small medium enterprises in Turkey. These two types of companies have different reflections to corporate governance.The researcher used quantitative methods for measuring the reactions against corporate governance principles under the Turkish Commercial Code. Secondary data and primary data that support the argument are combined.Critical thinking about regulation effect to accelerate corporate governance affects on companies, however, traditional companies’ board structure and also business and corporate strategy are not adequate for applying new concepts. On the contrary, listed companies are ready as much as western companies for applying corporate governance principles.The results are researched that law enforcement is important factor for implementing corporate governance principles but just law power is inadequate for applying corporate governance principles entirely. The author recommends that some consultancy should be provided to the companies by the government or international institutions for a better application. In a word, a better application of corporate governance principles provides sustainable business in a global world.