To study heavy ion collisions at energies available from the Relativistic Heavy Ion Collider ~RHIC! ,w e have developed a multiphase transport model that includes both initial partonic and final hadronic interactions. Specifically, the Zhang’s parton cascade ~ZPC! model, which uses as input the parton distribution from the heavy ion jet interaction generator ~HIJING! model, is extended to include the quark-gluon‐to‐hadronicmatter transition and also final-state hadronic interactions based on a relativistic transport ~ART! model. Predictions of the model for central Au on Au collisions at RHIC are reported. PACS number~s!: 25.75.2q, 24.10.Lx, 24.10.Jv The beginning of experiments at the Relativistic Heavy Ion Collider ~RHIC! this year will start an exciting new era in nuclear and particle physics. The estimated high energy density in central heavy ion collisions at RHIC is expected to lead to the formation of a large region of deconfined matter of quarks and gluons, the quark gluon plasma ~QGP!. This would give us the opportunity to study the properties of the QGP and its transition to hadronic matter, which would then shed light on the underlying fundamental theory of strong interactions, quantum chromodynamics ~QCD!. Because of the complexity of heavy ion collision dynamics, Monte Carlo event generators are needed to relate the experimental observations to the underlying theory. This has already been shown to be the case in heavy ion collisions at existing accelerators such as the SIS, AGS, and SPS @1‐6#. As minijet production is expected to play an important role at RHIC energies @7#, models for partonic transport have been studied @8,9#. Furthermore, transport models that include both partonic and hadronic degrees of freedom are being developed @10,11#. We have recently also developed such a multiphase transport ~AMPT! model. It starts from initial conditions that are motivated by perturbative QCD and incorporates the subsequent partonic and hadronic spacetime evolution. In particular, we have used the heavy ion jet interaction generator ~HIJING! model @7# to generate the initial phase space distribution of partons and the Zhang’s parton cascade ~ZPC! model @9# to follow their rescatterings. A modified HIJING fragmentation scheme is then introduced for treating the hadronization of the partonic matter. The evolution of the resulting hadron system is treated in the framework of a relativistic transport ~ART! model @2#. In this paper, we shall describe this new multiphase transport model and show its predictions for central Au-on-Au collisions at RHIC.