Regulation of the private security industry in Mongolia is relatively recent with the first specific legislation dating back to 2000. In 2000, the State Great Hural(Parliament of Mongolia) passed the Law on Contracted Private Security Service and has been revised twice, by which ‘modern’ private security was legally born. The aim of this study is to compare and evaluate the regulation of private security in the Mongolia, Belgium and the United Kingdom. In particular, this study illustrates the differences which exist in the level of regulation governing the operation of the industry in these countries in four areas such as areas covered private security companies, entrance requirement for companies, restriction on the background of owner/management, restriction on the background of employee, training/education. The comparative study of the three countries shows an imperative need to make further amendments to the Law on Contracted Private Security Service. According to the findings, this study proposes the direction for constructive amendments to strengthen the Law on Contracted Private Security Service.