企業因為經濟自由化、貿易國際化潮流之影響，逐漸成為資本集中與技術密集之經營型態。為求擴充生產規模、增加產品種類、分散投資風險、拓展國際市場等目的，因而成立新公司或兼併其他公司，或購買其他公司之股份，或母公司與子公司交叉持股，而形成關係企業之組織型態，已成為普遍趨勢。職是，關係企業之經濟發展與經營模式，已然占有重要之地位。 關係企業具有特殊屬性，舉凡管理組織、生產規劃、人事制度、市場行銷、財務風險、獲利能力、公共事務與社會歸屬，均有相當程度之影響力。我國公司法對於關係企業專章之規範，仍有不足之處，導致受一九九八年亞洲金融風暴影響所及，爆發若干關係企業之經營弊端，其中以股票流通市場之證券交易違法行為，最為嚴重。綜觀其原因，除肇始於東南亞金融危機及國際不景氣環境外，亦顯示關係企業在股票市場存有許多問題，諸如負責人欠缺誠信、掏空公司資產，造成企業發生危機，發生多起上市或上櫃公司之經營弊端，嚴重損害公司、股東權益與債權人利益，並衝擊社會投資人與整體經濟，值得探討研究。 本論文研究方向，以法制理論、比較法學及實證案例為基礎，論述關係企業證券交易之違法行為，以股票流通市場為中心，並闡述近年來若干重要之關係企業案例，分析法院裁判之論處法律邏輯。包括關係企業之市場操縱行為（違約交割、沖洗買賣、相對委託、連續交易炒作行為）、關係企業「護盤」之違法性、關係企業之內線交易行為，等重要項目。亦討論關係企業藉由無形資產之高估或低估而買賣有價證券之非常規交易行為，兼述國際會計準則公報之規範，佐以實際案例研究。此外，亦闡論關係企業財務預測制度與證券交易違法行為之牽連、證券投資人之保護。 本論文內容之參考文獻資料，包括學位論文（例如前輩先進之博碩士論文）、教授學者之著作書籍、著名期刊與國內外網站資訊。所參考資料則以我國與美國法制文獻為主，至於其他國家之部分，則略以要旨參酌。最後，再針對作者執業律師參與關係企業案例之辯護瞭解，提出若干防弊機制之建議，俾供各界參考。 / UNLAWFUL ACTS BY AFFILIATED ENTERPRISES RESPECTING SECURITIES TRANSACTIONS WITH A FOCUS ON THE STOCK EXCHANGE MARKET Abstract Due to the impact of economic liberalization and trade internationalization, operations of enterprises have gradually become capital-intensive and technology-intensive. In order to increase production, expand product line, spread out investment risks, and develop international markets, enterprises have established new companies, merged with others, and purchased shares of other companies, or have engaged in cross-holding of shares between parent companies and subsidiaries. As a result, the formation of affiliated enterprises has become a popular trend. The economic development and business model of affiliated enterprises have likewise become important issues. Affiliated enterprises have their unique attributes; their management organization, production planning, personnel policy, marketing, financial risks, profitability, public affairs, and social affiliation have significant impact on enterprises. Due to inadequacies in the regulations on affiliated enterprises in Taiwan’s Company Law, several affiliated enterprises were exposed to have engaged in fraudulent business operations as a result of the 1998 Asian financial crisis. Among these, most serious were cases involving unlawful securities transactions in the stock market. An analysis of the factors leading to such anomaly shows that in addition to the Southeast Asian financial crisis and international economic slowdown, problems caused by of affiliated enterprises in the stock market, such as integrity and credibility issues on the part of the persons-in-charge and their swindling of company assets, resulted in corporate crises. Many incidents of business malpractices in public or OTC companies occurred, severely undermining the interests of companies, shareholders, and creditors, as well as those of the public investors and the overall economy. All these are worthy of further exploration and study. This paper uses legal theories, comparative jurisprudence, and empirical studies to discuss the unlawful activities in securities transactions by affiliated enterprises. This paper focuses on the stock market to explain the major cases involving affiliated enterprises in recent years and to analyze the legal grounds in the court’s decision on punishment. The cases covered include market manipulation by enterprises, default of securities delivery, wash sales, matched order, manipulation of series of transactions, the unlawfulness of stock market intervention by affiliated enterprises, and insider trading by affiliated enterprises. In addition, this paper discusses the transaction anomalies resulting from overvalue or undervalue of intangible assets by affiliated enterprises. Regulations on the International Accounting Standards gazette are explained and supplemented by actual case studies. In addition, this paper explores the inter-relation between financial forecast systems in affiliated enterprises, unlawful activities in securities transaction, and investor protection. Reference literature used in this paper includes academic dissertations, publications by professors and scholars, periodicals, and information from local and foreign Web sites. Reference materials are based primarily on literature on Taiwan and U.S. laws, supplemented by summary of information from other countries. Finally, recommendations of mechanisms to prevent malpractices are put forward, drawing on the author’s experience as defense lawyer for affiliated enterprises.