Corrective feedback and error correction are important tasks for ESL/EFL (English as a Second Language/English as a Foreign Language) writing instruction. Research findings showed that students’ major difficulty in error correction lies in their failure to detect errors. Also, researchers proposed that error analysis can be reinvented in the form of computer-aided error analysis, a new type of computer corpus annotation. Annotations on digital documents can be easily shared among groups of people, making them valuable for a wide variety of tasks, including providing feedback. This study developed a web-based online corrective feedback and error analysis system called WRITE (Writing Revision Instrument for Teaching English). With this system, teachers can make error corrections on digitized documents, on the general web browser such as Microsoft Internet Explorer, with online annotations in the same way as the traditional paper-based correction approach. The WRITE system can feedback correct answers, teachers’ comments, and the grammatical error type for each error to students. In addition, this system can provide users the annotation marks subject to different query conditions so that the problem of cognitive overload can be avoided. For error analysis purposes, this system can access the database and analyzes students’ errors and displays the results as requested. Students use WRITE will be able to effectively identify more errors. Moreover, the ways that the corrective feedback delivered through the online annotation system can be used by students to develop his/her corrective strategies.