Abstract: A model  describing a system with element theory is put forward to avoid the difference and inconsistency of the basic-element modeling. The affairelement modeling, matter-element modeling, relation-element modeling and basic-element model revising are included in the model . Also the modeling of relation among elements is proposed to normalize and conform the element modeling by adding, deleting, revising the basic-element and their characteristics. Hence， a case study of sharelearning teaching method is put into practice to illustrate the process of the proposed modeling in this paper.

Key words: Extenics; basicelement modeling; modeling of relations among elements; sharelearning teaching method