Insider trading is securities trading conducted by those who are classified as " the insider " of a company based or motivated by inside information which is very important and non concealead to the public. Such insider expects to obtain personal economic benefit, directly or indirectly , or that constitutes as short swing profit. An insider trading practice is contradictory to disclosure principle. The disclosure principle requires every company to sell the stock through the stock exchange floor. The disclosure principle must be uphold either for the interest of exchange management such as Jakarta Stock Exchange (BEJ), Surabaya Stock Exchange (BES) and The Capital Market Supervisory Board (Bapepam ) as controller. This thesis highlights the rules of Bapepam and stock exchange in conducting control/supervision on the exixtence of an insider trading, efforts to avoid it and the criterion that determine whether a person has conducted insider trading. Up to today no insider trading case uncovered despite of a number of supporting device can be made as evidence. In so doing, Bapepam as the last resort for investors must have obvious steps in handling the settement of an insider trading case and bring it to the court, besides dare to apply cumulative sanction, namely fines and imprisonment on insider trading as regulated in Article 104 of The Capital Market Law number 8 year 1995 (UUNo. 8Tahunl995).