Abstract:Abstract:Critical thinking cultivation in EFL teaching has been at the forefront of Chinese and foreign educators’ initiatives. And with recent development of critical thinking studies in English writing context, the importance of exploring the strategies to foster critical thinking ability in writing has been widely acknowledged. Therefore, this study attempts to explore the effectiveness of task-based cooperative writing instruction to critical thinking and English writing development. Experimental results suggest that: 1) task-based cooperative writing could effectively cultivate college students’ critical thinking abilities in general and students’ critical thinking affective disposition and cognitive skill both get enhanced to a significant degree; 2) College students’ critical thinking ability is positively and significantly correlated with their writing proficiency. Among the critical thinking sub-dispositions, there exists a positive correlation between students’ writing quality and truth-seeking as well as maturity. And the correlations between the writing quality and all the critical thinking sub-skills are positive and significant.