A statistical information collecting system and device for finding the detailed state of traffic flowing in a network to effectively reduce the traffic flow by sending statistical information from a statistical information collection apparatus to a collector device. A statistical information collection system with a statistical information collection apparatus comprising a collector device, in which the statistical information collection apparatus receives packets and collects statistical information from the received packets, and sends the collected statistical information to a collector device; the statistical information collection apparatus contains flow information including flow identification conditions for identifying flows that the received packets belong to, and sorts the statistical information on the collected packets for each flow identified by the flow identification conditions while referring to statistical information sorted for each flow, and the statistical information collection apparatus decides the transmit intervals for each flow for sending the statistical information to the collector device.