摘要:European countries started integration of company law from the 1960s. European countries groped for the system which be able to get country agree, aiming at unifying company law. In recent years, in order to correspond to change of environment, such as development of an information technology, and generating of a financial crisis, European Union focuses on corporate governance and is carrying out company law reform. This paper focuses on an argument until it catches the integrative company law which is the foundation of the corporate governance in today’s European Union. First, this paper considers confrontation between the member states produced in the arguments from 1960 to 1990 which aimed at establishment of company law of unific European countries. This paper shows clearly that European countries next shifted the system of the member states into the harmonizing plan by the arguments from 1990 to 2000 which it aimed at establishing an alternative system. Furthermore, this paper clarifies having shifted the plan into integration of corporate governance and having carried forward the step to a new stage by reform in and after 2000 when the Societas Europaea was born in Europe. Integration of the company law system in the European Union is the result to which the 1960s which tried unification of the corporate system to 30 years were applied and which was constructed as a system where it can agree. This result will surely have the power of overcoming the monetary crisis of these days. Furthermore, European Union is gazing at formation of the previously more detailed company law system. This experience of European Union has a possibility of forming the standard in the world, as an example of a success of the advanced experiment which unifies a regional company law system. This paper analyzes the company law institutional reform over this honest long period of time. Then the mission of Europe as an integrated area and a battle of right protection of a member nation are caught systematically. This paper has the novelty of arguing how the corporate institutional reform in European Union is utilized in the future reform.