The purpose of this research is to examine the effect of corporate governance implementation quality on debt ratio. The samples of this reserach is non banking companies which include Swa sembada s rating of CGPI (Corporate GOvernance Perception Index) score in 2003 2004 2005 and 2006. The number of samples is 33 companies. First of all a measeure of corporate governance implementation quality is CGPI score by IICG ( Indonesian Institute of Corporate Governance). Secondly a measure of debt ratio covers current debt to total asset (CD/TA) non current debt to total asset (NCD/TA) total debt to total asset (TD/TA) current debt to shareholder s equity (CD/E) non current debt to shareholder s equity (NCD/E) and total debt to shareholder s equity (TD/E). The result of regrission analysis showssignificantly that there are positive effect of CGPI score on TD/TA and that of CGPI score towards TD/E. This result is consistent with finding of LItov (2005) but controverse with findings of Harford (2005) Black et.al (2003) and Salman and Farid (2007).