The current trend in the mobile telecommunication market is to provide variable valueadded data services over GPRS networks. The evolution from the GSM Intelligent Network (IN) system which has been widely deployed towards the GPRS IN system allows the operators to build new data services in a cost-effective, speedy way. In order to achieve this evolution smoothly and efficiently, it is necessary to consider the essential differences between the GSM IN and the GPRS IN which would do virtually effect on the system implementation. Those differences, together with the corresponding key technologies are discussed and analyzed in this paper. Some value-added services which are hopeful to be deployed firstly on the commercial GPRS IN system are proposed. It's believed that some enhancements to the architecture specified by the 3rd Generation Partnership Project (3GPP) could enrich the features and types of the GPRS IN service, which are also our further study topics.