本研究通过结构方程模型，探讨二语口语动机、努力程度和二语口语水平的关系。结果表明，努力程度直接影响口语水平，实际努力程度解释力最大。动机变量通过努力程度的调节间接影响口语水平，其中理想自我和学习态度贡献力最大，而应该自我的作用有限。提升类工具动机、口语自信和口语兴趣之间存在共变关系，且作为理想自我的支持变量影响口语水平。抑制类工具动机和家庭影响互相关，并与提升类动机共同作为应该自我的支持变量影响口语水平。

The study explored the relationship of L2 motivational self system and motivated effort to L2 speaking proficiency through structural equation models. Results indicated that effort affects L2 speaking proficiency directly, and actual effort’s explanatory power is the biggest among all the independent variables. Motivational variables affect L2 speaking proficiency indirectly via effort, among which ideal L2 speaking self and attitudes to L2 speaking are the biggest contributors to L2 speaking proficiency, while ought-to L2 speaking self plays a limited contributing role. L2 speaking instrumentality-promotion, self-confidence, and speaking interest inter-correlate with each other, and serve as supporting variables to shape ideal L2 self, and affect L2 speaking proficiency indirectly. Instrumentality-prevention and family influence inter-correlate with each other, together with instrumentality-promotion, serve as supporting variables of ought-to L2 speaking self, and have limited and indirect influences on L2 speaking proficiency.