Within multi-agent systems, it is almost impossible for multiple Web agents to completely share a same semantic vocabulary. Because of incomplete information and ontological heterogeneity, an agent can partially understand the contents of other ontologies. This makes multi-agent communication rather difficult. In this paper, we utilize semantic approximation for implementing better multi-agent communication based on partial shared distributed ontologies, and hence achieve coordination query among multiple agents. We also developed a multi-agent coordination system based on semantic approximation.