The purpose of this study was to examine the influence of consumer's ethical consumption consciousness and lifestyle on sustainable fashion. The data was analyzed by reliability analysis, factor analysis, cluster analysis, one-way ANOVA, Duncan's multiple range test, and multiple regression. The major results of this study were as follows. First, three factors of sustainable fashion were identified: eco-friendliness, recycling, and safety. Second, three factors of ethical consumption consciousness were identified: social ethics, environmental ethics, and public ethics. Based on these factors, the subjects were categorized into three clusters (high, middle, and low ethical consumption consciousness group). Third, four factors of life style were identified: pursuit of brand, appearance, cautiousness, and information. Based on these four factors, the subjects were categorized into three clusters (brand/appearance, cautiousness/information, and unconcerned group). Fourth, three factors of ethical consumption consciousness significantly influenced eco-friendliness factor of sustainable fashion. Also, the recycling factor of sustainable fashion was influenced by social ethics, environmental ethics, pursuit of brand, and pursuit of information. The safety factor of sustainable fashion was influenced by environmental ethics, public ethics, and pursuit of information. The results of this study suggest that practical and various environmental education need to be provided to consumers, because high environmental ethical consciousness consumers evaluated sustainable fashion positively. Additionally, accurate information on eco-friendliness, recycling, and safety of clothing products would need to be provided by fashion businesses through various routes, because those with information-pursuing lifestyle were found to have deep interests in sustainable fashion.