This research aims to analyze the effect of good corporate governance mechanisms on financial performance as measured by return on assets, return on equity, and TobinsQ. In addition, this study aims to analyze the differences in financial performance between the financial enterprises (banks) and non-financial enterprises which predicted better in the financial sector as it is a regulated sector. Variabels which use are board of commissioners size, independent commissioner size, board of directors size, audit committee size, the proportion of managerial ownership, and the proportion of institutional ownership. This research uses a quantitative approach with panel data analysis model. This research use population of financial and non-financial listed business enterprise which winning Annual Report Award 2006-2008 with 5 year observation period. By using a population of 6 financial enterprises and 9 non-financial enterprises, the research found that the variable size of the board of commissioners has no significant effect to financial performance, the independent commissioner size variable has significantly positive effect to ROA and ROE financial enterprises but has significantly negative effect to TobinsQ. In addition, the variable size of the board of directors has significantly positive effect to ROA of financial enterprises and ROE of financial and non-financial enterprises, the audit committee size variable has significantly negative effect to financial performance, and the variable proportion of managerial ownership has significantly positive effect to ROA and ROE financial enterprises but has significantly negative effect to ROE non-financial enterprises. The variable proportion of institutional ownership has significantly positive effect to TobinsQ and otherwise has significantly negative effect to ROA and ROE of financial enterprises. In addition, this research also proves that financial enterprises have lower financial performance than non-financial business enterprises which implement GCG mechanism.