The implementation of Good Corporate Governance (GCG) at regional-owned enterprise will obviously affects the sustainability of that company, hence the improvement of society’s economic and welfare in that region will be achieved.  This research aims to measure GCG implementation of regional-owned enterprises in South Sumatera Province, Indonesia using the assessment instrument in which its indicators and sub-indicators are the combination of GCG assessment of national state-owned company and OECD. The indicators cover: 1) The infrastructure of GCG; 2) transparency; 3) accountability; 4) responsibility; 5) independency; and, 6) fairness. There are 5 companies participated as the sample with 3 organs of each became the respondents. In collecting the data, this instrument of assessment was designed and developed by the researchers in a-5-Likert scale with the options from ‘Strongly Disagree’ (1) to ‘Strongly Agree’ (5). Gathered data were analyzed through descriptive statistics method, i.e., presenting the data in the form of percentages and followed by description. The analysis data revealed that: 1) regional-owned enterprises in Sumatera Selatan Province ‘moderately’ fulfilled the indicator of ‘Infrastructure of GCG’, evidenced by the highest response given by the majority of respondents to this indicator fell into the scale of “Adequately Agree”. Meanwhile, the implementation of the other 5 indicators of GCG was ‘very good’ in which the most choice given by the respondents to these indicators was on ‘Strongly Agree’. These findings suggest that as enterprises which serve public, the stakeholders need to ensure good governance of all regional-owned enterprises has been well-carried out..