More particularly, the dog collar buckle included in the dog collar is provided with a rivet-type fastener and a lower magnet spaced apart from each other in a lower buckle in which the free end of the dog collar band is provided so as to be adjustable in length The upper and lower magnets are spaced apart from each other in the forward and backward directions in a state in which the center of the insertion hole and the engaging hole coincide with each other. The upper buckle is automatically retracted by the magnetic force of the upper and lower magnets provided at intervals from each other so that the head portion and the pillar portion of the hook can be easily hooked so as not to be detached from the insertion hole . The present invention is characterized in that upper and lower buckles 10 and 30 and a free end portion 5 in which a fixed end portion 4 is fixed to the rear of the upper buckle 10 and in which several length- And a dog collar band (2) that is adjustably installed on the dog collar (30)； The lower buckle 30 is provided with band fitting portions 34 and 33 for respectively fitting the free ends 5 of the collar band 2 to the front and rear of the lower buckle main body 31, 33 of the free end portion 5 which is fitted in the band fitting portion 33 is formed on the upper portion of the lower buckle body 31 between the pair of band fitting portions 33, And the upper head portion 36 and the lower side column portion 37 are formed in the upper portion of the lower buckle main body 31 at the rear of the front side band fitting portion 34 And a lower magnet 39 is installed on the upper portion of the lower buckle body 31 at the rear of the stopper 38； The upper buckle 10 is provided at its rear end with a hook 38 at the front side of the upper buckle main body 11 having a band fixing portion 17 to which the fixed end portion 4 of the collar band 2 is engaged, A key groove 12 in which the column portion 37 of the latching hole 38 is engaged is formed in the
