An IC-tag reading necessity determination method and system include preparing success rate information indicating a rate of success of receiving a response from an IC-tag to a first signal each time a set or a plurality of sets of transmitting the first signal to the IC-tag a plurality of times is performed, performing processing to transmit a second signal to a target IC-tag from a reading apparatus a plurality of times to acquire response reception success/failure information indicating success/failure of reception of a response to the second signal; and determining whether the target IC-tag is to be read based on the success/failure of each time indicated in the response reception success/failure information and a rate of success of each time indicated in the success rate information.