The present invention is to provide a diaper structure, which includes a diaper main body formed by a fabric layer, an anti-leak layer and an absorbent material layer sequentially from the inner side to outer side thereof, and a communication chip and a metal antenna attached to the outer surface of the anti-leak layer and connected with each other to form an RFID tag. Thus, when the absorbent material layer absorbs the urine passing through the fabric layer and the inner surface of the anti-leak layer is in contact with the urine on the surface of the absorbent material layer, the change in the relative permittivity of the anti-leak layer causes a change in the impedance value of the metal antenna and consequently a change in the wavelength of the electromagnetic wave signal transmitted by the RFID tag, thereby enabling rapid detection of a soaking wet condition of the diaper.