我國證券交易法第171條規定內線交易之刑事責任，2004年修法時，同條第2項新增加重內線交易罪，亦即犯罪所得達一億以上者，法定刑由原先的三年以上十年以下，加重為七年以上。新法施行之後，在司法實務中引起相當大的爭議。以多年前喧騰一時的前總統女婿趙建銘等人涉及台灣土地開發股份有限公司股票內線交易案（以下簡稱台開案）為例，該案自2006年12月27日作成一審判決後，迄今已歷經最高法院四次發回更審，全案審理迄今已超過9年。台開案之所以一再被最高法院撤銷原判、發回更審之主要理由之一，即是最高法院與高等法院間對於內線交易犯罪所得之計算有不同見解。無獨有偶的是，在美國違反1934年聯邦證券交易法第10條b項之內線交易罪，依聯邦量刑規則亦以犯罪所得之多寡，作為決定被告量刑範圍的依據之一。因此，在美國內線交易罪之司法判決中，被告亦常以判決對犯罪所得計算有誤為理由提起上訴。與台灣相同的是，負責審理上訴的聯邦各巡迴法院之間，對於犯罪所得的計算亦有不同見解。本文嘗試探尋我國現行法之立法歷程及司法實務之實踐，由立法理由及司法判決中，試圖找出我國法制解釋之線索。接著再以台開案為中心，觀察與整理歷審判決理由，藉以瞭解爭議所在。接著再從比較法出發，解讀美國司法判決的相關案例，從中尋覓內線交易犯罪所得計算於美國法制下之爭點，以作為我國法制下解釋內線交易犯罪所得之借鏡。最後，以上述討論為基礎，提出本文對我國內線交易犯罪所得計算方法之見解。

Section 171 of Securities Exchange Act has been amended in 2004. The offense of insider trading has been imposed at lease 7 years in prison if the actor gets more than one hundred million Taiwan dollars. However, how to measure the gain resulting from the insider trading offense is controversial among courts. For example, the insider trading scandal in which the son-in-law of former President is involved has been tried for more than nine years. The major issue in that case is the calculation of the defendant's gain. Coincidently, the similar issue is among U.S. circuit courts. The Eighth Circuit takes ＂net-profit approach＂ in U.S v. Mooney, however the Tenth Circuit adopts the ＂market absorption approach＂ in U.S. v. Nacchio. Since the Supreme Court has not yet taken this kind of case, the controversy is still unclear till now. In this research, the authors try to understand the statue from the legislative history. But, the reasoning behind the statue is vague and contradictory. Then this research compares several insider trading cases and tries to figure out the main issues in judicial opinion. Furthermore, the author reads U.S. v. Nacchio, U.S. v. Mooney and other U. S. cases and tries to learn lessons from U.S. debate. Based on the above discussion, this research provides its own approach.