Web Services play an important role in providing an interface between end user applications and the underlying technologies. Being the base for distributed, decentralized systems, web services replace closed, centralized systems increasingly. Distributed collaborative systems represent the next step for the accomplishment of increasingly more becoming tasks. They promise a more flexible use of available resources as well as higher scalability, robustness, manageability, and extensibility. A promising and innovative new technology for developing distributed collaborative systems is given by Grid computing. In this paper we describe a webservice which is responsible for the realization of the necessary remote data access and data management. This service can be used by persons or application to register and manage replicas of data sets. The communication between the service and clients isrealized by the exchange of standardized XML messages using the Simple Object Access Protocol (SOAP). Consequently, this data management service is platform, programming language and system neutral.