In this paper, we investigate a scenario of RFID applications referred to enable a group of RFID tags which have been scanned simultaneously by a reading device, is literally called grouping proof problems. After examining the existing “Yoking Proof” protocols of RFID, this paper proposes a protocol called “Select-Response” Grouping Proof. Instead of waiting the computation result from the tags as previous protocols, the new protocol uses a new mechanism that the reader actively selects the demanded tags to fulfill the verification. With this fundamental change, our protocol neutralizes the threats of denial of service attack, which is suffered by the “Yoking Proof” protocols, and provide collision-free and missing tag identification properties, which would offer great help in the practical applications.