The unfair trading practices on capital market are a kind of fraud and they damage fairness of capital market. Also, they may chase away a sound investor from capital market. As a result, they have an adverse effect on economic growth and development of state. That is the reason why a regulatory policy is needed to keep watch unfair trading practices on capital market. That is ‘The Capital Markets Act’. But it is not effective because a regulatory process is very complicated and takes long time. Due to the characteristics of security crimes, the current process to deal with it is that the self regulatory organizations of Korea Financial Investment Association and Stock Exchange recognize an offense first and notify it to Financial Services Commission, a national regulatory organization. The national regulatory organization prosecutes only after going through a rather complex and duplicated process of deliberating autonomously through its capital market inquiry committee and securities & futures commission and then going to the prosecution. Because of this, it takes a lot of time from the occurrence of security crimes to the indictment by the prosecution, so the current system to investigate and inqurie into security crimes is not effective. Moreover, there are serious problems in the investigative procedure for unfair trading such as manipulation and insider trading. For example, the evidences collected by administrative agencies are inadmissible in criminal trail and it takes too much time for the administrative procedure. The suggestion to solve this problem is, first, the introduction of a special judicial police system, second, the abolition of plural commissions, such as capital market inquiry committee and securities & futures commission, and third, establishment of a consultative body between the prosecution and financial supervisory organizations. The three suggestions are worth being considered for more effective investigation process into security crimes. However, prior to these institutional remedies, the reflective study of the functions and the main duties of financial supervisory organizations must be preceded. When a special judicial police system is introduced and the plural commissions are discontinued, the main works of the financial supervisory organizations can be reduced to investigation and punishment. It may improve the efficiency of investigation and punishment, but they will not be able to use its ability to administer and supervise the stock market demanding administrative regulations. Therefore, the suggestion to form a consultative body between the prosecution and financial sepervisory organization is reasonable for efficient and effective investigation and punishment.