Abstract: To meet the function requirements of Modelica-based hybrid modeling platform for multi-do-main physical system,a kind of COM-based system architecture is adopted and a totally self-developed visual graphical modeling system—MWoks is implemented.A sentence object and a kind of data structure of model object based on sentences are designed.Based on the sentences of a model,dynamic bidirectional convertion between graphics view （including Icon view and Diagram view） and text view of the model is realized.Also a trifurcate tree structure storing the information of the hierarchy of models is proposed.And then a block object based on the entity set representing a model’s part is implemented,as well as the drag-and-drop modeling from the re-usable models （i.e.components） in MSL （Modelica Standard Library） to the Diagram view of current model is realized.Finally a modeling instance on the MWorks system is given.