Abstract: A strap buckle with self-locking function, incorporating a frame shaped holder (15) with a shaft (1) extending laterally to the inner of the frame, which shaft carries a double-armed locking member (12), pivotably against the action of a resilient member, which locking member is adapted to cooperate with end gable (21) of the frame, thereby locking a part (19) of a strap between the locking member (12) and said end gable, whereby, for the purpose of providing a simple, easily assembled and reliable strap buckle, both arms (20,22) of the two-armed locking member (12) are situated inside the outer frame (18,21) of the holder (15), and the locking member (12) is provided with a central non-round, oblong transverse groove (13), and that the shaft (11) has a non-round, elongated cross-sectional shape corresponding to that of the groove (13), whereas the resilient member is an integral part of the locking member (12), where the portions (25) about the groove (13) are elastically resilient, and the holder (15) as we