— In this paper, performance of recently modified two-port time-domain passivity approach is evaluated under serious time-varying communication delay. First, recently proposed two-port time-domain passivity approach is reviewed. A packet reflector with wireless internet connection is used to introduce serious time-varying communication delay of teleoperators. Average amount of time-delay was about 180(msec) for round trip, and varying between 175(msec) and 275(msec). Moreover some data packet was lost during the communication due to UDP data communication. Even under the serious timevarying delay and packet loss communication condition, the proposed approach can achieve stable teleoperation in free motion and hard contact as well.