XML, emerging as a standard for data representation and exchange on the Internet, plays an important role in varieties of applications. According to the analysis of the functional and performance requirements of WIS/GISC data access, a meteorological data subscription system is designed based on metadata presented by XML and the asynchronous communication mechanism. The background, usage, and scope of the subscription system are introduced. The scheme of describing meteorological metadata and order and dissemination information metadata represented by XML, the subscription functionality technology, the system design pattern, and the system workflow are given. The design has been implemented in the Beijing GISC system and meets the application requirements satisfactorily.