Certain glycopeptides and peptides provide a taste improving function, particularly a kokumi taste imparting function. In particular, these glycopeptides and peptides per se may be used to impart the kokumi taste to foods or seasonings and to improve the kokumi taste in foods with the use of seasonings which contain the glycopeptide(s) and/or the peptide(s). These glycopeptides and peptides may be used in a wide range of applications and provide a strong effect of improving the taste and imparting a kokumi taste, that is, enhance the basic tastes and impart thickness, spread, continuity, unity, and the like, associated with the enhancement of the basic tastes.