An experimental system for dialogue structure analysis based on a new type plan recognition model for spoken dialogues has been implemented. This model is realized by using four typed plans which are categorized into three kinds of universal pragmatics and a ldnd of taskdependent knowledge related to common action hierarchies. The experimental system is characterized by higher modularity and computational efficiency through defining a hierarchical usage order between these knowledges. The system can grasp a dialogue structure making it possible to solve problems related to spoken dialogue interpretation.