This document specifies a composite IP packet selector in Metering Process of the IP Flow Information Export protocol (IPFIX). The composite selector is realized by combining a sampling selector using systematic or random sampling technique followed by a hash- based filtering selector computing the hash function on 5-tuples information (source/ destination IP address, source/destination port number, port). Taking flow sampling into account in packet selection, the designed composite selector could better solve the short-flow lost problem meeting in simple systematic or random sampling selector.