This article is about an action research which has been conducted in the course English 3 for 40 second-year students of Early Childhood Education Faculty, Hong Duc University. The research implemented the activity of self-recording as a homework after teacher instructed pronunciation rules and assessment criteria. The components of pronunciation which were focused are sounds, stress and intonation. There are two circles in this action research. After the first circle, there were supplemental actions to improve the intonation practice. The findings from tests, observation, and students’ document express that the self-recording has had a positive impact on students’ pronunciation when they pronounce English.