Written Corrective Feedback (WCF) in writing classes is fundamental to interactions between teachers and students about students' writing and to help students further improve their writing. As one of the main feedback sources, teachers' cognition (e.g., teachers' thoughts, knowledge, and beliefs) needs to be probed to properly understand teachers and their teaching (Borg, 2006). Currently, there is little research regarding teachers' cognition and their practice of offering WCF in mainland China. The purpose of this study was to explore ESL teachers' knowledge of, experience with and practice of WCF, and to investigate the connection among these aspects. The participants were teachers of English from a major normal university. The phenomenological methodology was used to explore teachers' cognition and practice of WCF when teaching writing to undergraduate and graduate students. The study employed a triangulated approach that included a questionnaire administered to 55 teachers, interviews with two teachers and a study of the two teachers' feedback responses to 68 students' papers/journal entries, which were collected to further explore the interviewees' practice of WCF. Questionnaire data was statistically aggregated and tabulated. The interview data was analyzed using Hycner's 15 steps. The teachers' responses on students' papers were analyzed according to WCF types (direct CF, indirect CF, metalinguistic, focus of feedback, electronic CF, and reformulation) and error types (organizational errors, stylistic errors, and linguistic errors) and the results were tabulated. Findings indicated that ESL teachers possessed different levels of knowledge concerning WCF and used a varying number of WCF types to target error types. Most teachers were not well trained or provided with opportunities to be equipped with the necessary skills, to further improve their cognition and practice of providing feedback. Differences existed between teachers' perceptions of the employment of WCF and their actual practice of it. The findings are an indication that administrators should consider employing multiple strategies to better equip teachers of writing to teach and provide feedback more effectively and efficiently. The future of providing WCF on writing in mainland China is dependent upon a workforce that excels in feedback cognition and practice. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]