The purpose of this study was to examine the effects of brand-related and corporate-realted knowledge on brand-name extension and corporate-name extension, respectively in fashion market. Here, it is designed into three types of brand and corporate awareness; 1) Higher brand awareness and corporate awareness, 2) higher brand awareness and lower corporate awareness, and 3) lower brand awareness and higher corporate awareness. For this study, questionnaires were administered to 700 single women in twenties. The questionnaires were designed to measure evaluations of brand-name extension and corporate-name extension and brand-related and corporate-related knowledge in terms of familiarity, use experience, self-assessed knowledge, evaluation of attributes and attitude. Employing a sample of 621 women, data were analyzed by Multi-Regression analysis. Major findings of this study are summarized as follows; 1) In level of higher brand and corporate awareness, the evaluations of brand-name extension were influenced by corporate-related knowledge such as brand use experience, evaluation of brand attributes and brand attitude. Also, the evaluations of corporate-name extension were influenced by both brand-related knowledge such as brand attitude and corporate-related knowledge such as use experience of product awareness and lower corporate awareness, brand-related knowledge such as evaluation of brand attributes and brand attitude was identified as the important factor in the evaluations of brand-name extension. 3) In level of lower brand awareness and higher corporate awareness, corporate-related knowledge such as attitude toward corporate was identified as the important factor in the evaluations of corporate-name extension.