A congestion avoidance technique using active packet pacing for interconnection network is presented. In this technique, communication packets are sent intermittently by adjusting the inter-packet gap in order to match up packet flows precisely. Therefore the network congestion is avoided. The gap is pre-calculated for each communication according to the communication hop, and the value is explicitly passed to a sending function. Performance evaluations for some collective communications were performed by using an interconnect simulator and a benchmark program was executed on an actual machine. Finally, the scalability and effectiveness of packet pacing in interconnection network were confirmed.