There are an increasing number of DBMS vendors thinking of integrating XML data management into traditional relational database, with wider use of XML. In this case, a comprehensive evaluation methodology is needed to evaluate the XML engine in RDBMS correctly. In this paper, we analyze the characteristics of XML engine and propose an evaluation strategy of XML engine in a RDBMS. We believe that the evaluation should include functional evaluation and performance evaluation, and cover several major aspects of DB such as storage, query and update. Then we designed an evaluation scheme for the XML engine in RDBMS according the strategy. The scheme describes an evaluation scene and contains a data set, workload and index set. The data set reflects the characteristics of both data-centric and document-centric XML data. The workload covers all of the requirements of XQuery in W3C. The index set covers the aspects of storage, indexing, query and update. In the end, we complete an experiment to test an actual computer system using the proposal. The result shows that the proposal is proper.