Small and medium-sized construction sites are most serious in Occupational Safety and Health in the construction industry. The safety consulting engineering has been launched, in 1995, to improve the safety environments and prevent serious injuries and fatalities accidents. The purpose of this study is to analyze the effect of the safety consulting engineering for small and medium-sized construction sites. This study conducts a number of interviews with experienced contractors, consulting engineers, etc. And the questionnaire survey was peformed with 111 respondents. This paper presents several improvements to increase the efficiency of the safety consulting system.