||The success of future ATM networks depends heavily on the ability to deliver a wide range of services. Service scheduling scheme in ATM node is one of the key issues to guarantee the diverse QoS requirements. Numerous schemes have been proposed in recent years in order to provide guaranteed services. Among the proposed schemes, Earliest Deadline First and Fair Queueing systems have received most attention in recent research. The former has a desirable feature that it is able to minimize the number of packets that violate their deadlines, while the latter is able to provide fairness and end-to-end delay bound. However, all the mentioned schemes assume infinite buffer case and concern only the delay performance and/or fairness property, but totally ignore another factor that can also be affected by service scheduling schemes: the cell loss performance. However we argue that it is more practical to consider a finite buffer model when designing the service scheduling scheme. In this thesis, we propose two novel service scheduling schemes that take also the cell loss performance into consideration besides the delay performance and/or fairness property. The first one, the Earliest Deadline First for Finite Buffer (EDF-FB) scheme can maintain the desirable properties of the EDF scheme and can also reduce the cell loss at the same time. The second one, the Modified Fair Queueing for Finite Buffer (MFQ-FB) scheme provides an end-to-end delay bound comparable to other fair queueing systems but with a much lower cell loss probability. In addition, an analytical method for estimating the cell loss probability for the MFQ-FB scheme has also been proposed.