The structural parameters of alanine zwitterion hydration in water were studied by means of the integral equation method in the framework of the 1D-RISM approximation. According to the calculations, ∼5.9 water molecules are located in the nearest environment of the COO-group, and the nearest environments of the NH3 + and CH3 groups contain ∼5.5 and ∼11.6 water molecules, respectively. The number of hydrogen bonds formed by the COO- and NH3 + groups is 4.3 and 2.4, respectively. The data obtained did not reveal hydrogen bonding of the nitrogen atom of the NH3 + group, whereas there is a possibility for hydrogen bonding of the methyl group with water molecules. No structuredness of water molecules near the CH fragment of the hydrophobic moiety was found.