品牌聯盟是市場上經常被運用的行銷策略，廠商藉由搭配另一個品牌共同推出產品，不僅增加原本產品的屬性，更讓消費者對於新產品產生更高的信心與正面的態度。消費者在對品牌聯盟產品形成態度的同時，也對原本單獨兩品牌產生了新的評價，使得消費者在品牌聯盟前後對於個別品牌的態度出現差異，造成品牌聯盟的外溢效果。本研究之目的在探討品牌聯盟類型中的組成份共品牌，是否會因為不同品牌知名度的組合，而影響消費者對品牌聯盟的態度。另外當品牌參與聯盟之後，消費者對品牌態度的改變，是否受其本身知名度以及在聯盟中擔任角色的影響。本研究設計一個2（主品牌知名度高/低）x2（成分品牌知名度高/低）x2（品牌聯盟成功/失敗）=8組的實驗，利用問卷瞭解消費者在各種組合下對品牌聯盟以及個別品牌的態度，再利用統計分析比較彼此的差異。 透過對214份有效問卷的分析，研究發現品牌知名度確實是影響消費者對品牌聯盟態度的因素。此外，消費者在品牌聯盟之後對個別品牌態度的變化幅度，會受品牌聯盟市場反應的好壞，品牌本身知名度，以及此品牌在聯盟中擔任角色的交互影響，而造成外溢效果的差異。品牌聯盟市場反應好壞不必然同時影響消費者對聯盟中兩個品牌的態度，消費者傾向於將品牌聯盟的成敗歸因於主品牌上，使主品牌的外溢效果大於成分品牌。另外品牌外溢效果同時會受品牌知名度與聯盟中主附品牌角色不同的影響。低知名度加上主品牌的組合最容易產生顯著的外溢效果。 / Brand alliance, also called co-branding, is a useful marketing strategy which helps an existing brand to leverage associations, strengthen its image and influence consumers’ attitudes by linking itself to other brands. A special case of brand association is ingredient branding, which highlights a product’s ingredient brand in order to signal the quality of co-branded products. While consumers perceive a co-brand and form attitudes to it, the attitudes toward each constituent brand are also influenced, causing the spillover effect. This study tries to find out if brand awareness is the key factor to impact consumers’ attitudes to a brand alliance. Further, it explains how spillover effect differs between a main brand and an ingredient brand when either positive or negative information about an ingredient branding product is presented to customers. Experiments are conducted to compare an array of consumer’s attitudes and spillover effects of ingredient branding products. Main brands and ingredient brands of different awareness levels are paired alternatively to design eight co-branding conditions. The study finds out brand awareness is a key factor that influences consumer’s attitudes toward a brand association. The combination of two high-awareness brands gains the more positive attitudes than other awareness combinations. However, the level of awareness has little to do with the strength of spillover effect. Attitudes to a brand alliance, positive or not, do not necessarily influence the attitudes to either allied brands. Spillover effect is not a symmetrical phenomenon, and therefore one brand usually gains more spillover effect than their counterpart. Generally the main brand in an ingredient branding has higher spillover effect than the ingredient brand.