在網路日益發達的社會中，藉由網路分享的網路評論也隨之受到大眾之關注。根據資策會調查之結果發現台灣使用網路的消費族群中高達81%的消費者在購物前會使用網路口碑做為購物之參考。網路評論的盛行也使得網路評論之有效性受到業界及學者的關注。 在探討評論有效性的過程中，學者發現讀者通常會比較重視負面之網路評論所提供的訊息，而這樣的現象被稱為負面偏誤(Negativity Bias)，且因為網路環境虛擬且存在著許多風險，信任對於網路互動扮演著十分重要的角色。因此，本研究旨在探討信任及讀者態度對於正負面網路評論之有效性影響。 本研究透過前測選定正面及負面的網路評論，並以實驗設計法將正網路評論及負面網路評論分為兩組進行實驗，讓受測者分別閱讀正負面網路評論並進行問卷之填寫，共計291份有效問卷，其結果顯示: 1.負面評論有較高之評論效果 2.信任正向調節負面偏誤 3.讀者與該評論對商品的態度一致，則讀者的信任受到增強；反之則信任受到削弱 ;In an increasingly developed society, the public′s attention is drawn to online reviews. According to the III (Institute for Information Industry) and the results of a survey they undertook; they discovered that up to 81% of Taiwanese consumers use online reviews as a reference when shopping. As the online review has grown increasingly popular, so too, it has also become an important factor for the industry and scholars. During the process of discussing online review validity, researchers found that readers would usually pay more attention to negative online reviews. Such a phenomenon is called negativity bias, and because of how the virtual network operates—including potential risks from people writing misleading online information—trust towards network interaction plays a very important role. Therefore, the purpose of this study is to explore the effectiveness of trust and the readers’ attitude on the effectiveness of both positive and negative online reviews. This study selected a positive and negative online review through pretest. The Experimental Design and Research Method we created to conduct this experiment included dividing our subjects into two groups. One group read only the positive review, and the other saw only the negative review. Afterwards, the subjects were then required to fill out a questionnaire, which resulted in a total of 291 valid questionnaires at the end of the study. The results showed that: 1. The effect of negative online reviews will be greater than positive online reviews. 2. Trustworthy positive moderate negative bias. 3. If the readers and the online review are consistent, the reader′s trust should be enhanced; but on the contrary, the trust is weakened.