Web-based learning systems are one of the most interesting topics in the area of the application of computers to education. Collaborative learning, as an important principle in constructivist learning theory, is an important instruction mode for open and distance learning systems. Through collaborative learning, students can greatly improve their creativity, exploration capability, and social cooperation. This paper used an agent-based coordination mechanism to respond to the requirements of an efficient and motivating learn-ing process. This coordination mechanism is based on a Web-based constructivist collaborative learning system, in which students can learn in groups and interact with each other by several kinds of communica-tion modes to achieve their learning objectives efficiently and actively. In this learning system, artificial agents represent an active part in the collaborative learning process; they can partially replace human in-structors during the multi-mode interaction of the students. Web-based learning systems are one of the most interesting topics in the area of ​​the application of computers to education. Collaborative learning, as an important principle in constructivist learning theory, is an important instruction mode for open and distance learning systems. , students can greatly improve their creativity, exploration capability, and social cooperation. This paper used an agent-based coordination mechanism to respond to the requirements of an efficient and motivating learn-ing process. This coordination mechanism is based on a Web-based constructivist collaborative learning system, in which students can learn in groups and interact with each other by several kinds of communica-tion modes to achieve their learning objectives efficiently and actively. they can partially replace human in-structors during the multi-mode interaction of the students.