In this review we present Raman spectroscopic studies on the structure of water in aqueous solutions. Various interpretations and analyzing procedures of Raman bands of liquid water, especially those of O-H stretching band, are introduced. The structure and hydrogen-bonding properties of water which exist in aqueous polymer systems and biologically important solutions analyzed with contours of O-H stretching band are described. Effects of chemical properties of solutes and size of water domains surrounded by polymer chains on the structure of water are discussed.