High numbers of work accident prove that work safety can no longer be denied. There must be a system to manage safety, especially in construction sector, which give the biggest contribution of work accidents in Indonesia. The system to manage safety is usually called as Safety, Health, and Environment system (SHE system). However, the success of SHE system is affected by safety maturity level of company. In fact, the numbers of work accident is still increasing even SHE system has been applied in the company. This research is conducted to develop safety maturity model to improve safety and project performances. This research will take a portrait of the existing safety maturity level of Indonesian construction companies. After knowing the existing level and the indicators that have not been fulfilled, a development will be given to improve the existing safety maturity level. The variables of the research are safety policy, safety institution, safety cultures, safety maturity levels, safety performances and project performances. This research will be conducted through a Delphi and survey questionnaire methods. The results of this research are improvement of safety maturity model and suggestion of improvement actions to improve safety maturity level.