The demand against the OH&S (Occupational Health and Safety) from the companies or the agencies which operate an management system is increasing. ISO 45001 was established by ISO (International Organization for Standardization). This standard is international and authoritative standard of OH&S. Also this standard provides guidance for the use of the organization to improve occupational health and safety performance by preventing occupational accidents and diseases. This paper is to review how the OHSAS 18001:2007 to ISO 45001:2018 focusing on reasons for transitions. Additionally, Therefore, this paper shows case study for understanding ISO 45001:2018 implementation.