The purposes of this study were to analyze factors of mass customization for hair salon`s customers and to identify the differences among groups segmented by mass customization level. The self-administered questionnaire was used for data collection. The respondents were 423 women using hair salons. Factors of hair salon`s mass customization implementation were sanitary condition & hair salon`s staff, hair styling technique, communication service, tangible service, monetary support, convenience service, and visible service. Hair salon`s customers were categorized into the high-level of needs group, the middle-level of needs group, and the low-level of needs group. The high-level of needs group consisted of university students or women with a higher education or higher income. This group selected beauty salons by the promotion or advertisements, preferred their own unique hair style or a little-fashionable hair style, and showed a lower level of patronage. The middle-level of needs group consisted of university students or women with a higher education or higher incomes. They selected hair salons by service prices, preferred a basic hair style, and showed a midium level of patronage. The low-level of needs group consisted of women with lower education or lower income. They selected beauty salons by career of hair dressers or the promotion or advertisement, preferred highly fashionable hair style, and showed high level of patronage.