Accident prevention plan it a construction site should be analyzed and made with risk evaluation and management, from recent year, in Korea. Accidents occurred in construction site are related to all parties such as owner, main and subcontractor, labour. But analyzing some relationship between main and subcontractor is very important to estimate what risk between then are existed in a site. There are some different aspects concerning with risk management between them. Everywork has its own risk in there, This is the reason why everywork which are made by subcontractor himself should be evaluated for risk level. And main contractor should provide for subcontractor to prevent each risk at the work, all the time.