The construction industry is very dynamics and includes many changes. To measure construction safety culture (CSC), the interactions and causal relationships among the key factors (which were called the Enablers and Goals) must be taken into consideration. This paper developed a CSC dynamic model, utilizing system dynamics (SD) modelling technique, to capture the interactions and causal relationships among the five enablers (Leadership, People, Policy and Strategy, Partnerships and Resources, and Processes) and Goals of CSC. A CSC index, developed through SD modelling, was used as an indicator for assessing the CSC maturity levels, and identifying gaps that must be bridged to reach a maturity. The simulation results revealed that an increase of the five enablers' values enhanced the Goals value, as well as the CSC index. An organization could perform a number of policy experiments to underline areas for safety improvement to enhance the CSC index, and select the best policy that matches its situation.