Online tutoring has received more and more attention. Moreover, teacher-student interaction has great influence on students’ learning. The main purpose of this study was to investigate the effect of teacher-student interaction on students’ learning achievement in online learning environment. In this study, 46 elementary school students participated in this study. This result indicated that the students’ learning performance was significant improved after a semester of online tutoring. Moreover, the result indicated that the influence could effectively predict students’ learning achievement. In the final of the study, some suggestions were proposed to help the online tutors to manage their online tutoring.