Despite the extensive research on second language learning motivation, very little research has been conducted with Chinese learning motivation and the focus of the research has been limited mainly to identifying types of motivation. Considering the popularity of Chinese as a second language and the lack of research on Chinese learning motivation, the study aims to illustrate the process of motivational changes in learning Chinese from the sociocultual perspective. The data were collected from the researcher’s own autobiographic diary written while she was learning Chinese. Using the framework of an Activity Theory, the data were analyzed to find factors affecting the participant’s motivatonal changes. The findings indicate that the participant’s motivation was affected by dynamic interaction of mediational tools, relationships within the community, and different roles of the learner. The findings imply that the level of motivation is affected by how the learner resolves the tensions among those factors to move forward to the goal of becoming a multilingual speaker. The study may provide a methodological insight into L2 motivation research by analyzing and describing a longitudinal Chinese learning experience from a first-person point of view.