Recently, Radio frequency identification (RFID) has been applied widely, but still have some problems in the library searching system. The challenge of RFID searching system is it can only point out the approximate area, but not the location even if where the side of the bookcase is. This paper is proposing a new method and antenna structure by providing two omni-directions which narrow down the searching area and recognize the book's location on the bookcase. The proposed is a dual-radiation pattern of RFID tag. It is a two-port structure and combined with two RFID chips and a pair of Yagi-Uda. Two different radiation patterns are created, which will recognize whether the target is in front of the searcher or is in the opposite side to help locating. This tag can direct the searcher and locate the target more precisely than before. After several rounds of test validation and modification, the design provides a rapid searching mechanism. The structure of this antenna is simple and very flexible for users, it becomes a new solution for searching system in the future.