2008年9月所爆發的「三鹿集團毒奶粉」事件，是近幾年來引起民眾關注最巨的公共食品安全事件。這個食品安全危機擴及全球，引起各地消費者的恐慌，而台灣也是受害的國家之一，因此本研究要分析比較危機前後，是否會影響到消費者購買的決策。本研究以消費者購買決策模式(EKB Model)作為理論基礎，選擇「資訊搜尋」及「選擇評估」兩步驟為研究主軸，並觀察「涉入程度」與「生活型態」對消費者購買決策的影響。經過實證分析後，獲得以下幾項研究發現：在三聚氰胺事件過後，消費者對於各個訊息管道之資訊會更重視，其中又以「網路評價」之影響力最高。而大部分消費者在選擇評估時，對於「價格」及「過去經驗」之權重下降；反之，對於「品牌」及「售後保證」的重視程度則是升高，顯示消費者傾向相信較有品質保證之食品。此外也發現不同類型消費者所重視之因素確實有差異，故可針對目標客群規劃行銷活動。

The incident of Sanlu's melamine contaminated milk was discovered in September 2008, and caused the most severe public issue of food safety incidents in recent years. The food safety crisis had expanded to the whole world, and caused panic across the consumer in many nations; Taiwan is also one of the countries affected by the incident. Therefore, we intend to analyze and compare how the crisis affects consumer purchasing decisions before and after the incident. In this study, the Consumer Purchasing Decision Model (EKB Model) is adopted as a theoretical basis, in which "Information search" and "Select assessment" are selected from decision-making process as two key decision objectives; in addition, the impacts of "Involvement" and "Lifestyle" to consumer purchasing decisions are jointly analyzed. The key findings are as below: after the melamine incident, consumers will pay more attention to the information search about products, in which "network assessment" has the highest influence. Besides, the weight of "price" and "past experience" in the select assessment are decreasing for most of consumers; while the weight of "brand" and "warranty" are significantly increasing. It indicates that consumers tend to believe the food with good quality assurance. Moreover, we also found the differences in decision factors among various types of consumer; thus, the supplier can plan particular marketing activities to target customer.