Two new quinochalcone C-glycosides, hydroxysafflor yellow A (1a) and tinctormine (2a), were isolated from Carthamus tinctorius L. (Compositae) together with carthamin, safflor yellow B and safflomin C. The structures of 1a and 2a have been determined by spectroscopic methods including heteronuclear multiple-bond multiple-quantum coherence and linked scan FAB-MS. The latter compound (2a) was demonstrated to have potent Ca2+ antagonistic action.