In Korea, Private security companies has steadily grown and amounts to 2,051 places as of November 30, 2002. Private security in korea is carrying out firm name role assignment to have held the police and public peace environment change factors for a standard faithfully, and protects social a little property that is a basic purpose, and it is spare no efforts in loss prevention. In spite of numeral increase of private security companies, private security companies have many problem. Moreover, they mostly did not have any remarkable in-house expertises in their own business under tough conditions. Under the unfavorable circumstances including insufficient investment and education in private security guard, there have been actually little further studies on private security business in practices. So this study mainly focused on addressing the installation security business managed by authorized companies, which amount to 96%(1,963 companies) of total 2,051 domestic security companies. Furthermore, the study formulated and modeled a series of business procedures in private security companies. A series of business procedures of private security companies can be modeled as follows : Setting of a business scope and aim market ⇒ Marketing, Contact from customers(On-line or Off-line) ⇒ Diagnosis of security target ⇒ Submission of security operational plan ⇒ Estimation of security operational plan,decision ⇒ Contract ⇒ Employment, selection of security guards ⇒ Nomination of security guard instructors ⇒ Education & training of security guards ⇒ subscribe to insurance of damage liability ⇒ Commitment and placement of security guards ⇒ Establishment and preparation of security planning ⇒ Field management and procurement of relevant security service.