Portals are a means integrating entergration information through a portlet, which is a presentation component. It is the essence of data interaction between portlets. This paper proposes an approach for extending the interface of a portlet and implementing a portlet cooperation by supporting the communication between portlets. The approach is based on an established portlet Specification , a WSRP Specification, and an analysis of existing data exchange methods. This approach allows the exchange message of structured XML between portlets to complete the work together.