The number of students in each English class at Nha Trang University is about 50 students. The time for all skills is only sixty periods including two periods of an introduction and two periods of a listening test. In other words, the time for practicing oral communication of each English non-majored student is limited in class. The question of how to make non-majored students practice English more outside the class has been taken into consideration. The research I have conducted will partly answer the question. Three classes of one hundred and fifty non-majored students were experimented with to practice a dubbing technique themselves under the lecturer's instructions. In 15 weeks, each student, after seeing some samples would practice shadowing and dubbing fifteen videos in which he or she plays the role of all characters and then he or she records audio at home or performs in class depending on the lecturer's requirement, does not only to develop their pronunciation but also improving their intonation and rhythm. The results were that a large number of them find themselves more self-confident in speaking in front of the class. Especially, their level of speaking has considerably improved and developed. However, the lecturer's workload is significantly increased.