The industries of polyester in Taiwan have been mired in difficulties, due to much higher labor cost than underdeveloped countries. The research through related theories such as competitive strategies. According to the theory of competitive advantage, our enterprises need to strengthen the competitive by improving product value and making the transition. Therefore enterprises should avoid over-competition. Besides, they need to emphasize the characteristics of polyester and develop the new markets in the other specific fields. We analyzed and aimed to discover the competitive strategy. We stared with the industry analysis and followed with a case study. By way of the SWOT, Five Forces and comparison with the same trade with the case company, we are to explore the managerial strategies of the case company, to reason out how to keep the case company’s competitiveness in the global industry.