Researchers have contributed themselves to increasing students' motivation in English classrooms for long years, so role-playing activities are often applied in English class. However, motivation increasing does not happen to all English learners due to role-playing, for learner characteristics are often ignored. Therefore, this study, based on 149 freshmen at a four-year institute of technology, is to explore the relationship between English learners' positive attitudes toward English learning and such learner characteristics as academic major and gender through role-playing. The results reveal that learners of different academic majors and different genders have different positive attitudes toward English learning regarding their interest in English, their expectation of attending English class, their courage to speak English and their self-confidence in English class. This study also gives suggestions and reflections on teaching materials and approaches in English classrooms.