Despite all the regulations aimed at building reliable and responsible Tokyo Stock Exchange and JASDAQ etc., observed wrongdoing has increased--think of Livedoor scandal and FOI window-dressing that 140 shareholders sued against Tokyo Stock Exchange and Auditing Firm, etc.. Now Institutionalization of real Code of Ethics and Conduct should be applied to 'Business Codes of Conduct' in IPO regulation of all Japanese Stock Exchange Markets. In this thesis, the following three are considered. (1) Learn the history of Code of Ethics and Conduct in USA regulations like SOX Act made after the case of Enron and WorldCom (2) Review the issues in 'Business Codes of Conduct' in Tokyo Stock Exchange regulations and the importance of Institutionalization of Business Ethics (3) Proposal of the revised 'Business Code of Conduct' to Tokyo Stock Exchange regulations from the ethical points of view, referring to Sec. 406 of SOX Act in USA, UN Global Compact, Keidanren Corporation Action Charter, OECD Principles of Corporate Governance etc..