The goles of this study were that we calculated the difference between the emission factors currently used officially and the emission factors that calculated by atmospheric dispersion modeling results and actual field measurements of dust concentrations and that we investigated how we applied to the emission factors appropriate to the reality in Korea. At the results, we calculated the Business As Usual ambient dust concentration concerning U.S. EPA method emissions, and we thought that the emission reduction efficiency had to be 99.7% if the ambient dust concentration that measured in this study could be satisfied. In other words, U.S. EPA dust emission calculation method is very overestimated than reality, so it is important that our country obtain reliable construction site dust emissions estimation methods by continuous researches.