There is disclosed a pharmaceutical composition of stabilized [Leu¹³]-motilin-Hse. The composition comprises at least one of organic acids and salts thereof, as a first stabilizer, and pH thereof is adjusted in a range of 5.5 - 8.0. The composition may contain at least one of substances selected from saccharides, amino acids, proteins and salts thereof, as a second stabilizer. Conversion of [Leu¹³]-motilin-Hse into [Leu¹³]-motilin-Hse-lactone is suppressed by increasing pH value and deamidization in asparagine residue at 19-position is suppressed by the presence of the organic acid or salt thereof.