This paper propose Multicast routing performance evaluation scheme using the PC based router. It is well known that most of CPU's instruction throughput is consumed in multicast traffic by interface's interrupts and memory copy. We measured PC's performance in the teleconference over broadband networks using DVTS to determine actual cause of performance problem. As a result, we confirmed that due to ATM-NIC's interruption on a multicast server gave greater influence on multicast routing performance.