This paper proposes an implementation of a Java networking application programmer's interface (API) for Asynchronous Transfer Mode (ATM) networks. ATM is considered as the network for the future. Since more and more Web-based applications are written in Java these years, it is of high importance to support Java network programming on ATM in order to support World Wide Web style applications on ATM networks. In this paper, we first give a brief introduction of ATM networks. Then, we give an overview of the architecture of applications on ATM networks. Next, we describe the implementation of our Java networking API on ATM. Finally, we point out the weakness of the current Java networking API in relation to ATM networking and discuss future research directions. Our implementation provides a platform for developing Java applications on native ATM protocols and demonstrates the feasibility of designing a new Java networking API on native ATM protocols.