The influence of KCl on the orientation of the Uracil molecules adsorbed on the grey aqueous silver sol has been studied by means of surface enhaned Raman scattering (SERS) spectra. The experimental results have been compared with those of W. S. Oh's in detail and discussed analytically. It is shown that the molecules of Uracil lay flat on the silver surface, while, after adding a small volume of an aqueous solution of KCl to the silver sol solution, the molecules of uracil under go a reorientation from flat-lying state to the state of perpendicular to the surface Via O-4.