This study proposes a conceptual model based on both self-determination theory (SDT) and expectation-confirmation theory (ECT) using physical education as an example. It is important to try integrating SDT and ECT together given that satisfaction is a common core in both theories. In the proposed model, need support confirmation is influenced by support expectation and perceived support, while need satisfaction is influenced by support expectation and need support confirmation. Accordingly, being influenced by need satisfaction, self-determined motivation has a positive influence on students' participation intention in optional PE courses. Finally, the discussion and limitation about the proposed model are also provided.