A macrolide derivative, i.e., a hydrate of erythromycin salts, has a molecular formula of C37H67NO13.A.nH2O, n=1.0-11.0, in which A is an organic acid or an organic acids, selected from lactobionic acid, thiocyanic acid, maleic acid, fumaric acid, thiocyanic acid, acetic acid, methanesulfonic acid, benzenesulfonic acid, nicotinic acid, lactic acid, citric acid, tartaric acid, aspartic acid, glutamic acid and phosphoric acid. The hydrate has better storage stability and is suitable for the manufacture of a medicament.
