In the WAP data extraction method of the present invention, all of the data packets passing through a WAP gateway are captured. Primary filtering is performed by determining whether each of the captured data packets uses the IP address of the given WAP gateway as an intermediate IP address, or has a port corresponding to a WAP protocol. Whether a Mobile Identification Number (MIN) is present in a header of data filtered in the primary filtering is determined. Whether the MIN is identical to a registered MIN is determined if a MIN is determined to be present. An IP address or a port number included in the header is registered, while the data packet is stored if the MIN is determined to be identical to the registered MIN. Secondary filtering is performed on the data packet having the IP address or the port number, and data filtered through the secondary filtering is stored.