At　present,　the　enterprise　theories　in　Neo-classical　Economics　and　New　Institutional　Economics　both　focus　on　enterprise＇s　growth　in　the　supposition　that　the　enterprise　have　formed,　even　if　the　Evolutionary　Economics　is　trying　to　bring　forward　the　formation　theory,　but　it　failed　because　of　lacking　of　the　standard　and　consistent　model.　This　paper　studies　on　the　enterprise＇s　formation　mechanism　based　on　the　CAS.　It　divides　into　three　parts.　The　first　part　Points　out　traditional　enterprise　theories　in　Neo-classical　Economics　and　New　Institutional　Economics　are　weak　in　the　formation　theory,　as　well　as　the　Evolutionary　Economics　owing　to　its　still　inconsistent.　The　second　part　introduces　the　basic　philosophy　and　theory　method　about　the　CAS,　including　the　Emergence　and　the　Self-organization　Theories.　In　the　last　part,　we　study　on　the　enterprise＇s　formation　mechanism　based　on　CAS.