Building strong brand equity has been the most effective method to extend market share and ensure profits. Brand extension strategy by using well-established mother brand names also becomes the most efficient way to enter a new market. The first objective of this study is to conceptualize and evaluate fashion brand equity. The next purpose is to investigate the relationship between mother brand equity and extended brand attitude. The survey was conducted from the 15th to the 26th of June 2009. We conducted a survey with 200 university students and 182 samples were analyzed. The data was analyzed by SPSS 12.0 with reliability analysis, frequency analysis, factor analysis, regression analysis and One-way ANOVA analysis. The results of this study are as follows. Firstly, the factors of brand equity based on customers were "Brand Satisfaction", "Brand Reliability", "Brand Personality/Value", "Brand Characteristic", and "Brand Edge". Secondly, the order of brand equity based on customers in this study was Polo, Beanpole and Tommy Hilfiger. Lastly, results revealed that brand extension was positively influenced by all factors of mother brand equity.