商標的基本功能在於表彰商品及服務的來源，並且與他人的商品或服務能夠區別，亦包含對該商品成分、組成、質量及外觀之綜合評價。緣依商標法第一條規定：「為保障商標專用權及消費者利益，以促進工商企業之正常發展，特制定本法」，可知商標法之立法目的，不僅在保障商標專用權人，同時亦兼顧消費者之權益。然在國際貿易實務中存在的真品平行輸入問題，同一商標的真正商品，在未經輸入國的商標權所有人同意下，逕行自國外輸入的行為。平行輸入商品與進口國的相同品牌商品相比，由於各國匯率與生產成本不同，或因商標權授權金額的差異，加以平行輸入商品並未負擔在進口國建立商譽如廣告、行銷、規費及售後服務等成本，使得平行輸入商品價格較進口國商標權人和其經銷商具有價格優勢。平行輸入損害了商標權人的實質利益，甚至造成商譽的損害，而使輸入行為之合法性受到了質疑，商標權人往往採取相應的手段來阻止平行輸入的行為的發生，因此引發了商標權與平行輸入問題的探討。然在國際貿易領域，平行輸入的合法性問題在不同的國家仍有不同的態度和看法，即使同一國家在不同時期也有不同的態度。

The function of the trade mark is to identify and distinguish particular goods possessing certain characteristics in composition, ingredients, quality and the like. Therefore, the trademark law is formulated to safeguard trademark rights, but also consumer’s interest. However, there are parallel imports existing in reality of trade. The parallel imports are generally defined as genuine goods, and are imported for sale into another country without the trademark owner's authorization. Parallel imports undermine normal distribution channels and frustrate authorized dealers who challenge the premiums paid to the trademark owner for genuine goods when competitors are underselling them. Due to various factors in each country, such as costs for local marketing, promotion, advertising, regulatory compliance and product liability should be passed along to local consumers. Therefore, trademark owners, their licensees and authorized distributors understandably believe that unauthorized distributors benefit unfairly by escaping these financial burdens. Besides, the parallel imports also cause negative consumer experiences that damage the goodwill and reputation of the trademarks. After the authorized distributors complain that they are being undersold, the licensees want to stop these parallel imports and the problem begins. National legal systems are remarkably inconsistent about whether and under what circumstances, parallel imports violate trademark laws. The national view depends largely upon how a trademark's function is defined and also upon whether the judicial precedents have sided with consumers or with manufacturers and distributors.