所謂交叉持股，係指二以上之公司，基於特定目的之考量，互相持有對方所發行之股份。我國規範交叉持股之法律，包括公司法及證券交易法，而公平法在結合之規範上亦有涉及。惟基於競爭法維護市場競爭秩序之立場，公平法對交叉持股之規範核心，厥為藉由結合之管制以防範市場力量集中後經濟力之濫用。 在計算結合案交叉持股是否已達公平法第六條第一項第二款之結合門檻時，依同條第二項規定，應將與該事業具有控制與從屬關條之事業所持有或取得他事業之股份一併計入，但因公平交易法並未明定「控制與從屬」之定義，故是否參照公司法關係企業專章之定義，有不同見解；而「一併計入」之計算基準，依條文文義及實例說明，應採相加計算，對此本文均有分析與探討。

The meaning of cross-holding is that, based on some specific concerns, companies will own each other share. In Taiwan, there have Company Law, Securities Trading law and Fair Trade Law governing the captioned matter. Concerning the issue of cross-holding, the mission of the Fair Trade Commission, by the control of merger entities, is to prevent the monopolistic behaviors which derived from the concentration. In determining whether the holding rates of a merger above the threshold of paragraph 1(2) of clause 6 of the Fair Trade Law or not, pursuant to clause 6 paragraph 2 of the Law, the ownership of the dominant and subsidiary shall be included as well. Currently, the Fair Trade Law did not define the subject of dominant and subsidiary, opines differ on this matter. Besides, in calculating the cross-holding rates, we should aggregate the ownership of the dominant and subsidiary directly. These topics above are discussed in this article.