An anti-collision method is provided for a radio frequency identification (RFID) system including a reader, and two or more tags each having an ID. The anti-collision method includes transmitting an ID request value from the reader to the respective tags, the ID request value containing one or more of the codes forming the ID, receiving the ID from at least one of the tags which contain the ID request value, when a plurality of IDs collide, requesting the tags for a value representing a position of collision, and receiving the value representing the position of collision from the tags and identifying the IDs of the tags. Because collision pattern of the bits of respective IDs is recognized, and a plurality of IDs are recognized, the number of transmissions between the reader and the tags can be reduced.