This thesis is striving to answer the problems are : should legal due diligence, legal audit and legal opinion be conducted in the process of the Initial Public Offering (IPO) in the capital market. How is the posotion of public stockholder in the Initial Public Offering (IPO). How far does the responsibility and obligation of the emiten in practice after the Initial Public Offering being conducted. In order to answer the questions of the thesis the writer had use a juridical normative approach and analitical descriptive. The conclusions of the research are : legal due diligence, legal audit and legal opinion are necessary to be conducted by a legal consultant in the process of Initial Public Offering (IPO) for the companies which are going to public. It is necessary for the investors to decide, if it is profitable to invest or not. The public stockholder as the investors after Initial Public Offering (IPO) was conducted having a strong legal status because of the confirmation notes (confirmation letter) being issued by the Indonesian Effect Central Custodian ( PT.KSEI) and being processed by the public stockholders as a prove of ownership of the public stockholders. Emiten have responsibility and obligation in implementation the principle of disclosure (disclosure principle) after the Initial Public Offering (IPO) was conducted