本研究对330名非英语专业大学生在一学期的英语写作学习过程中写作自我效能感和写作成绩的动态变化进行了追踪调查，通过交叉时序滞后设计并结合典型样本访谈，探究写作自我效能感对写作成绩的影响。研究结果表明：在一学期的时间内，学生的写作自我效能感与写作成绩均显著提升；交叉滞后分析证实学生的写作自我效能感是影响写作成绩的重要因素。同时质性访谈结果分析揭示了写作自我效能感对学生写作成绩的影响路径，表明写作自我效能感可以通过提升学生面对写作任务时的投入、动机和坚持性改善其写作行为，从而使写作成绩显著进步。

This study explores the dynamic changes of English writing self-efficacy and writing performance of 330 first-year Non-English Major students in an authentic college English writing course context and probes into the tentative effects of writing self-efficacy on writing performance by means of a cross-lagged design combined with typical case studies. The results reveal that both writing self-efficacy and writing performance of the students changed significantly after a semester of writing instruction and the writing self-efficacy has proven to be a significant source of effect on students’performance. Analyses of the interviews with the typical cases suggest that writing self-efficacy may have contributed to increasing writing performance via boosting students’cognitive engagement, motivation and persistence in face of writing tasks.