An inhibitor for an angiostatin I converting enzyme, its preparation method, and a food for inhibiting an angiostatin I converting enzyme containing the inhibitor are provided to improve the stability as food and to enhance an angiostatin I converting enzyme inhibitory activity remarkably. An inhibitor for an angiostatin I converting enzyme is prepared by treating Theobroma cacao, an extract of Theobroma cacao or their mixture by depolyphenol treatment. Also the inhibitor for an angiostatin I converting enzyme comprises Theobroma cacao, an extract of Theobroma cacao or an amino acid composition derived from their mixture. Preferably the depolyphenol treatment comprises at least one selected from solvent extract treatment, adsorption auxiliary treatment, enzyme treatment and ferric chloride method.
