本研究欲探索：當品牌推出延伸產品時，消費者對母品牌的認知、偏好及與延伸產品與母品牌契合程度上，對消費者所產生的行為意向。研究目的為：（1）消費者對母品牌的認知、偏好是否會影響消費者對延伸產品購買之行為意向；（2）消費者對延伸產品與品牌的知覺契合度認知，是否會影響消費者對延伸產品的購買；（3）分析「品牌認知與品牌偏好」和「產品知覺契合度」的關係，進而探討此兩點因素是如何影響消費者的行為意向。經過四次前測，以確認研究量表之架設。本研究使用大學生樣本，共取得有效問卷403份。結果顯示：消費頻率越高對於延伸產品的接受度越高；此外，消費者認知、偏好及延伸產品知覺契合度，均會對行為意向產生影響。研究建議，企業主可透過產品特徵或相關聯想，強化消費者對於延伸產品與品牌間之契合；此外，持續經營母品牌形象，強化使用者對品牌的喜愛，亦有助於延伸產品之銷售。

This research aimed at discussing the impact of the consumers' cognition, preferences and product extension perceived fit of parent brand on the consumers' purchase intention when there is a brand extension. The purpose of this research is to (1) discuss whether the consumers' cognition and preferences on parent brand have an impact on their purchase intention toward the extended brand (2) discuss whether the consumers' product extension perceived fit has an impact on their purchase intention (3) analyze the relationship between ”brand cognition and preference” and ”product perceived fit” to further study how these two factors affecting the consumers' purchase intention. Further, four pre-tests were conducted before verifying the research framework. The university students were taken as research samples and 403 valid questionnaires were collected. The findings showed that higher purchase frequency is associated with greater acceptance of extended product. Besides, all of the consumers' cognition, preferences and product extension perceived fit have an impact on the consumers' purchase intention. It is recommended that the corporations can enhance the consumers' cognition, preferences and product extension perceived fit through product characteristic or associations. In addition, continuously building the image of parent brand can improve the consumers' brand preference which is very helpful to product sales.