This study aims to determine how the implementation of the principles of Good Corporate Governance (GCG) principles in improving company performance. this research is also proven to create good corporate governance and can improve company performance. the research method used is qualitative method. data collected from books, magazines, and articles published in various scientific journals. the results of this study prove that the implementation of GCG principles significantly affects the improvement of company performance, such as PT Kereta Api Indonesia (Persero), Bank Jatim Dr.Soetomo Branch, Bank Syariah Mandiri Sidoarjo Branch, PT Taspen (Persero) and Mui Yogyakarta Cash Waqf Board.