This study aims to examine the effects of role-play activities based on scripts generated by students using label-sheets on the 4th-grade primary English learners in reading, speaking, and interest. Key words and sentences listed on worksheets were taught in both the experimental and the control groups. However, in the 4th lesson of each unit only the experimental class was asked to generate scripts. Each group of the class chose the setting and created dialogues by rearranging the key phrases listed on the label-sheet version of each worksheet. After 26 weeks` instruction all the students` achievement in reading and speaking was assessed. The results of the data analysis are as follows. The experimental group showed a statistically significant improvement in reading and speaking compared to the control group(p=.001, p=.000). In the affective domain, however, the student-generated script group showed a limited improvement: there was a statistically significant difference between two groups only in terms of engagement(p=0.044); most of the students in the experimental class responded very positively to the role-play activities based upon student-generated scripts, when they were asked to write down their feeling after each unit was over. This study shows that using a simple material such as label-sheets can have a significant impact in a primary English classroom. Thus, it is suggested that the student-generated script method be adopted for elementary school English role-plays. Furthermore, new English textbooks need to be organized to facilitate the method.