The present invention aims to provide an amino acid-containing granule preparation improved in the ease of taking medication than conventional products, which disintegrates rapidly. The amino acid-containing granule preparation of the present invention containing granules having a maximum particle size of substantially not more than 1000 μm and a bulk density of not less than 0.57 g/mL markedly improves ease of taking medication without impairing disintegration property, as compared to conventional amino acid-containing granule preparations.