電視節目中的置入行銷已經成為近年來極受爭議的傳播議題，因為它直接挑戰新聞媒體最重要的資產－新聞可信度。然而截至目前為止，針對新聞置入如何影響閱聽眾對新聞媒體可信度，尤其是電視新聞媒體可信度的實證研究，仍然非常有限。本研究認為，電視新聞中商業置入訊息的效果，如果是以犧牲新聞可信度作為代價，那麼這個效果也將隨著日益折損的新聞可信度，迅速消失。本研究因此針對商業置入訊息對新聞可信度的影響，以台灣電視新聞置入嚴重的夜間新聞節目，進行閱聽眾的實證研究。結果證實，有商業置入訊息的新聞節目，其新聞可信度確實低於沒有商業置入訊息的新聞節目。以置入的方式而言，明白標示置入廠商身分的電視新聞，其可信度高於隱瞞置入廠商身分的電視新聞。以置入的產品類別而言，置入高度爭議性商品訊息的新聞節目，其可信度會低於置入低度爭議性商品的新聞節目。如果採用低調置入的策略，閱聽眾對新聞可信度的評價比較高；而採用明顯置入的策略時，閱聽眾對新聞可信度的評價比較低。本研究也發現，較有能力辨識新聞節目中商業置入訊息的閱聽眾，評價電視新聞的可信度較低；辨識能力較低的閱聽眾，評價新聞節目的可信度則較高。而原本對新聞置入原本態度就趨於正面的閱聽眾，評價電視新聞的可信度明顯高過對新聞置入原本態度趨向負面的閱聽眾。 Product placements arouse huge controversies over news credibility and marketing values in recent years; however, there have been limited empirical studies focusing on the impacts of product placement messages on television news credibility. This paper argues that if the effectiveness of product placements is built right on the cost of news credibility, product placements' magic effects will soon go away. The current study therefore examined Taiwan's TV news programs in order to investigate the effects of product placement on news credibility. Results showed that TV news with product placements were perceived less credible than TV news without them. Moreover, in terms of the impacts of product sponsor identifications on news credibility, news with product placements revealing sponsor identifications were perceived more credible thanthose hiding sponsor identifications. Lower-controversial product placement messages were perceived more credible than those of higher-controversial products. Product placement messages packaged in subtle prominent strategies were perceived more credible than those packaged in prominent strategies. This paper also found that viewers with better ability to recognize commercial product placement message in TV news tended to rate TV news less credible. Viewers who previously had more positive attitudes towards product placements rated TV news more credible.