This research aims to investigate the impact of animated pedagogical agents on student motivation and achievement in English instruction. An XML-based authoring tool will be planned to support teachers to script multimedia teaching materials with animated agents and a stand-alone playing system will be provided in the classroom to display the materials for students. Two groups of participants from an elementary school in Taiwan will enroll in this experiment. One will be the experimental group and another will be control group. Data from a learning motivation survey will be collected from students in the experimental group after enrolling in EFL instruction which adopts animated pedagogical agents as teaching assistants in class activities. All students in the experimental group will be asked to complete the Instructional Materials Motivation Survey (IMMS) which has four scales, Attention, Relevance, Confidence, and Satisfaction, derived from Keller’s ARCS model. Results will be hoped to reveal the experimental group is mostly motivated by English instruction that uses animated agents. Investigation of student achievement will be carried out by a post-test in the experimental group and the control group. If results show the experimental group outperforms the control group in post-test, it will indicate applying animated agents in an English course is able to fostering learning performance.