根据MDA的思想，给出了用于统一描述数据模型的数据词典的逻辑结构，以数据词典的方式在元模型层上对数据模型进行统一描述，在数据词典的基础上分析了异构数据模型之间的数据映射关系。采用EBNF范式对描述映射关系的语法进行形式化定义和描述，同时给出映射关系的相关语义说明。在研究的基础上实现了数据映射功能，并投入实际应用，文中给出数据映射的应用实例。-This article present a kind of Data Mapping techenology based MDA,descr ipt the Mapping Relation conformably and normally based the united discr iption of Data Model. At the same time on the MetaModel level of Data Dictionary and based Data Dictionary this article analyse the Mapping Relation between heterogeneous Data Models.It define and Formalize the syntax of the Mapping Relation and provide EBNF to discribe the syntax of the Mapping Relation,present the semantic explaination and graphic symbols of modeling elements of Mapping Relation that can be used to visible modeling.Then on the base of the research of Mapping Relation,this article show how to accomplish the Mapping Relation and present a example of application of Mapping Relation.