The purpose of the study aimed to investigate the effect of the Readers Theater (RT) training on elementary school students. In particular, changes in the students' English reading comprehension before and after the RT show, comparison of the students' responses to English learning, especially English reading, the students' opinions on the RT activities, and the students' responses to English books were examined and analyzed. Additionally, the students' cooperative learning during the RT training was explored. The subjects of the study were 32 students in the sixth grade of a Taichung elementary school. Thirty-two students participated in RT training for almost forty-four days in order to perform in an RT show. Before the RT training, the subjects were requested to take the standardized English proficiency pretest and pre-study questionnaire. While participating in the RT training, the subjects needed to finish reading the selected English scripts. In the process of reading English scripts, the subjects were engaged in the reader's theater activities, including reading English scripts aloud, performing on the stage, and group work. After the RT training, the subjects were asked to take the standardized English proficiency posttests and post-study questionnaires. Considering the study findings, it was suggested that the teachers were able to utilize the RT activities in instructing students' English reading. With the stimulation of the RT activities, students could be motivated to be engaged in appreciating English books and obtained meaningful experiences from the characters in the plot. In addition, the teachers could foster students' cooperative learning through group work and enhanced the students' interest in learning English.