This study analyzes the business strategy of fast fashion through Zara, a successful fashion brand from Inditex Spain. An in-depth case approach is adopted based on extensive secondary research that includes literature and press releases published in Korean as well as English. The findings of this research demonstrate a speedy and flexible process occurring in the supply chain of its fast fashion business and the cooperation between the company`s headquarters and international subsidiaries. Zara`s headquarters executes four representative strategies: competitive market research, an integrated organizational structure, small quantity batch production, and a specialized distribution system. Zara`s international subsidiaries execute their own four representative strategies: differentiated international expansion, independent human resource management, small but fundamental IT, and maximization of store resources. These two core parts intimately work together to satisfy target customers all over the world by bringing competitive advantages to the fashion business and represent a key concept of Zara`s business strategy. The main drawbacks of case studies are limited validity and representativeness restraining the potential for making generalizations. However this case is considered sufficient to provide valuable insight and improve the understanding of operation strategy in fast fashion.