Abstract: An orally disintegrating formulation and its preparation are provided. The orally disintegrating formulation comprises an effective amount of a pharmaceutically active ingredient and a matrix, wherein the matrix contains an amino acid and pullulan. The orally disintegrating formulation can disintegrate rapidly in oral cavity and be taken without aid of water; Moreover, the formulation has a low hygroscopicity, so that the requirements for storing or producing the formulation is decreased, and the storage life is elongated to facilitate the administration by a patient and the preparation of the protein and vaccine drugs.