Abstract: ETL plays a key role in building and maintaining the data warehouse system.In order to facilitate the design，maintenance and modification of the ETL process，reduce the cost of design and maintenance，and reduce the cost of data warehouse’s building efficiently，the paper proposes a methodology for modeling ETL process based on an architecture graph，gives a good model to describe the ETL process.By representing the elements and relationships of the ETL process diagrammatically，it expresses the data’s coming and going，as well as their mapping and transformation relationships clearly and intuitively.It also supports the ETL designer to design the ETL process and develops the code efficiently，and improves the flexibility and reliability of the process of ETL design greatly.