In resent years, Social Enterprises have been proven to be a sustainable business model around the world. In Taiwan, most of the social enterprises are transition from Non-Profit Organizations. The scope of social enterprises are generally small, so how to maintain the organization's competitive advantage in the competing market become an important issue. For self-sufficient and sustainable development, social enterprises should provide good services or products to earn income. Then use the profit to help people in need. This study aimed to find the key factors that affect customer loyalty and provide suggestions for social enterprises to enhance customer loyalty. By the review of past literature, this study construct service quality, relationship quality and customer loyalty relationship model, and joining the altruism variable to explore its impact on customer loyalty. Also, confer the relationship between altruistic attribution and trust. Total number of survey forms responded was 402 , with 44 void and 358 valid. Respondents are the consumers form Children Are us Bakeries, Leezen and Sunny Kitchen. All of the companies are social enterprises. This study used structural equation model to verify the causal relationship between the variables. The result has come out with the following observations, 1. ‘Service Quality’ exhibits significant influence on ‘Trust’ and ‘Satisfaction’. 2. ‘Satisfaction’ and ‘Commitment’ exhibit significant influence on ‘Customer Loyalty’. 3. ‘Altruistic attribution’ exhibits significant influence on ‘Trust’. 4. ‘Altruism’ exhibits significant influence on ‘Customer Loyalty’. Finally, researcher provides some managerial suggestions for social enterprise managers and government.