This study bases on consumers in the make-up industry. The aim of the study is to investigate the moderating role of message trust in the relationships among product knowledge of customer and purchase intention. Questionnaires from 568 respondents were returned to test the model. The results of this study include: (1) product knowledge of customer will be negatively related to purchase intention. (2) The negative relationship between product knowledge of customer and purchase intention will be stronger where customer has high message trust.