An RFID system having a multi-subscription function, an RFID tag and an operation method thereof are provided. The RFID tag includes an RFID tag antenna, a tag storage unit, a sensor and a tag controller. The RFID tag antenna communicates with the RFID reader or the user terminal. The tag storage unit stores receives and stores user information transmitted from users. The sensor collects information on an object or environment to which the RFID tag is attached under the control of the tag controller. The tag controller classifies and arranges sensor information collected by the sensor for the user information of each user to generate tag information and transmits the generated tag information to the user terminal corresponding to the user information