The present invention discloses a system and method for implementing prepaid data services in a mobile communication network. In this system, a Data service Access Control Point (DACP), which is used for fulfilling price confirmation function and fee application function for data services, is added between a Service Control Point (SCP) storing prepaid account information of subscribers and a Prepaid Server/Content of Process Gateway (PPS/CP GW) used for data service charging. In the method of the present invention, by means of the interaction among a Packet Data Service Note (PDSN), a Home Authentication Authorization and Accounting (HAAA) server, the PPS/CP GW, the DACP and the SCP, the SCP deducts the fees from the prepaid account, and the PDSN controls the subscriber to utilize data service according to the fees deducted by the SCP. With the present invention, the subscriber can make prepayment for a data service by a prepaid voice account, which facilitates data service extension of mobile network operators and provides convenient data services for the subscribers.