This study investigated the impact of an online learning community project on university students’ motivation in learning Chinese as a foreign language. A newly proposed second language (L2) motivation theory—the L2 motivational self system (Dörnyei, 2005, 2009)—guided this study. A concurrent transformative mixed-methods design was employed to collect both quantitative and qualitative data through the pre- and posttest of a questionnaire. Results from paired t tests indicated a significant difference in the L2 learning experience aspect of motivation before and after the online project, while there was no significant difference in the other two aspects of motivation (i.e., the ideal L2 self and the ought-to L2 self). Specific motivating and demotivating features of the online project were identified from participants’ responses to an open-ended question.