The solvation structure of glucosamine in aqueous solution was investigated using Monte Carlo simulation at 298 K. The MCY rigid water model and ab initio glucosamine-water fitted potential were applied. The first hydration shell appears at 4.6 Angstrom from the center of glucosamine with a coordination number of seven water molecules where one water lies in the ligand's plane while two and four of them are about 2-4 Angstrom above and below the plane, respectively. Furthermore, the mobility distribution and orientation of the water molecules around the ligand have been intensively investigated and reported. (C) 2004 Elsevier B.V. All rights reserved.