Writing is one of the most important language macro skills that every language teacher should develop among his/her students
and written feedback is obviously an essential aspect of any English language writing course. While not all students are familiar with doing corrections and peer feedback may not work effectively yet, the use of teachers' written feedback on students' writing outputs which help students correct their errors in the most effective way is considered. Therefore, this study was conducted to find out if English Foreign Language Vietnamese teachers purposely give feedback to help their students improve writing and if the students effectively make use of them. The subjects of this the study are the 150 students randomly selected from four classes of primary education (PE), a class of nursery education (NE), a class of mathematics-physics education (MPE), and a class of chemistry-biology education (CBE) of Thai Nguyen Teacher Training College during the second semester of school year 2013-2014. The study concluded that there is a significant relationship between teachers' written feedback and students' performance in writing.