This study is for figuring out major components of construction quality infrastructure and suggesting improvement plan by benchmarking global best practice model and analyzing gap between the model and sample practice. Based on improvement plan, researcher could derive major characters and components of construction quality infrastructure, and also about the priority among core competency components of construction quality experts. The result showed that the 'human resource' was ranked the best priority followed by 'method' 'environment', 'equipment' among major characters and components of construction quality infrastructure. Also, for core competency components of construction quality experts, 'number of years in work places' was the best priority, and the 'professional knowledge on engineering' was another priority ranked. Far from general perception on competency components, 'academic education' ranked the last. It may allude that the current education system in this country is not effective in developing competency of quality engineers. In summary, this study shows professionalism of quality engineer is the most important thing in all the components.