The purpose of study was to explore the competitiveness among three Low-Cost Carriers(LCCs) in Korea and the difference of competitiveness according with service satisfaction of LCCs. We used niche theory which proposed three core concepts such as niche breadth, niche overlap and niche superiority, and analyzed the competitive relationships based on service satisfaction of LCCs. We used a professional survey agency to collect data from the customers who experienced all three LCCs(Jin-air, EastarJet, T-way). A total of 257 surveys were utilized in analysis. Factor analysis identified five underlying dimensions: reservation/ticketing service, ground service, in-flight service, operation service, and other service. Our findings indicate that Jin-air showed a higher superiority over EastarJet on niche superiority. Second, Jin-air showed a higher superiority compared to T-way on in-flight service, operational service, and other service. Third, EastarJet showed higher superiority over T-way on reservation/ticketing service and other service. However, T-way showed higher superiority on ground service compared to EastarJet. The result of this study provided differentiated marketing strategies for low-cost carriers, and the use of niche theory for competitiveness analysis which contributed to extending of research method and direction.