Abstract: Gelatin extracted from fish scale is not only a kind of nutritive food, but a prospective additive with higher safety used in food, drug and cosmetics fields. To get the gelatin , the inorganic substance(mainly hydroxyl apatite) in fish scale must be removed. The decalcification of fish scale was carried out in EDTA solution (decalcification agent). The process was monitored by titration. The method is exact and convenient to learn the decalcification rate and determine the terminal point during the decalcification process. The results of reproducibility and stability show that the method is feasible.

Key words: EDTA, titration, decalcification