由於消費者經常使用數種品牌的產品，或者依據使用時機，消費不同品牌的產品。因此，消費者是同時隸屬於不同的區隔市場，而不是「完全忠誠」的隸屬於某一區隔市場。本文主要目的在發展模糊集群分析法(Fuzzy Clustering)進行模糊區隔，改善傳統集群分析法的「互斥區隔」缺失，以增加數據處理的合理性與提升分析解釋的能力。本文針對臺北及高雄都會區的信用卡持卡人，使用利益變數，從事模糊市場區隔，並以隸屬度觀點，分析各區隔市場消費者行為特性。 本研究經由利益區隔變數，萃取出消費者的八個利益尋求構面，運用模糊集群法，區隔出「信用導向」、「品味導向」、「紅利導向」「安全導向」四種市場，並採用隸屬度的觀念，來計算市場大小及相對比例。藉由硬分類與軟分類的分析，可反應出市場的動態特性。研究顯示用卡的安全性最受重視，然而品牌忠誠性尚待建屯，同時臺北及高雄都會區的消費行為具有差異性。

　　　　　The consumers belong to various segmentation markets simultaneously, not to a certainly segmentation market, because the consumers often use products of many different brands to meet their different needs. The purpose of this study is to develop the fuzzy clustering method to do the soft segmentation and to improve the weakness of the hard segmentation. The soft segmentation makes the data process more reasonable and easier to explain. In this study, we use the credit card owners in Taipei city and Kaohsiung city to do the case study. The benefit variables are used to do the fuzzy market segmentations. According to the membership grade viewpoint, we also analyze the characteristics of the consumer's behavior of different segmentation markets. From the study, we get eight benefit variables and four major market segmentations. And we use the membership grade concept to calculate the market magnitude. The crisp partition and soft partition analysis can reflect the market dynamic feature. From the case study, it is shown that what the consumers are most is the usage safety of the credit cad. The consumers have little loyalties to the product of a certain brand. Besides, we also find there is difference between the purchase behavior of Taipei consumers and that of the Kaohsiung consumers.