To provide a buckle structure of a watchband which makes the coupling state of a buckle hard to release, and the small hole of a band hard to damage.

The buckle structure is constituted of a buckle frame 3 straddling two side walls 2, the buckle 1 having a prong 5 pivotally mounted around a coupling pin 4 in an opening portion side opposing to the buckle frame 3, and the band 10 securing the buckle 1 to an end portion of one band 9 and having a plurality of small holes 11 for inserting and removing the prong 5. A notch portion 3a where the front end portion 5a of the prong 5 pass through the buckle frame 3 in a vertical direction is formed in a corresponding location on which the front end portion 5a of the prong 5 of the buckle frame 3 abuts, and an opening and closing member 6 opening and closing the notch portion 3a by sliding in a longitudinal direction of the band in the buckle frame 3 is arranged so as to be biased by a resilient member (a plate spring) 7. The band is easily released because the opening and closing member 6 is slid, thereby the notch portion 3a is opened, and the front end portion 5a of the prong 5 turns below the buckle frame 3. The prong is easily released because the lower faces of the small holes are chamfered or inclined, thereby the coupling is easily released. The prong is easily returned. The small holes are hardly damaged.