The Fe complex formation of cyanidin-3-glucoside in acetate buffer solution (pH1.7∼6.0) was investigated spectrophotometically. Two different complexes were formed from cyanidin-3-glucoside and Fe^(3+), which had the absorption maximum at 543㎚ in the pH range 3.0∼4.0 and at 570㎚ in the pH range 5.0∼6.0 respectively. The molar ratio of the complex formed in the lower pH range was appeared to be 1 : 1, whereas that of the complex formed in the upper pH range was not able to be determined definitely. Among several organic acids examined, citric acid has shown the marked inhibitory effect on the Fe-tanthocyanin complex formation.