This study uncovers the under-explored influences that encourage teachers to incorporate task-based language teaching (TBLT) for teaching Chinese as a second language, and the process of teachers' pedagogical attempts at a Chinese university. Activity Theory (Engeström, 1987) was adopted as the conceptual framework. As a qualitative study, the analysis drew on data from interviews and classroom observations with eight teachers, and complemented by interviews with two directors and 17 students. The study reveals that teachers' pedagogical practice results from a process of negotiating the possible pedagogical tools to reach their teaching objectives in their context of teaching. In particular, teachers depart from the traditional teaching approach to incorporate tasks as a personal initiative in response to the perceived challenges in the effort to achieve their objectives. The study argues that compared to the constraints from the local education context, teacher beliefs and knowledge play a more critical role in shaping the extent to which teachers choose to adopt TBLT, as teacher beliefs and knowledge directly creates tension between TBLT as a tool and the desired objectives. The study proposes that the Problem-Solving Model (Havelock, 1969) for introducing pedagogical change gives teachers agency and ownership over TBLT, which may serve as a possible direction for realizing the pedagogical innovation.