At present, one of the important tasks of the ongoing college English teaching reform is to reform the traditional teaching mode,establishing the computer-based multimedia English teaching model. Based on the constructivist theory and the second language acquisi-tion theory, teachers who adopt the new teaching model should play multiple roles to maximize the teaching effect, being not only thecourse designer, organizer, but also the guide, helper and facilitator in the process of teaching students to construct knowledge and be en-gaged in classroom activities as well.
