The K9 glass substrate made in China were dipped in the silver melts at 270~300°C temperature, the Ag+-Na+ ion exchange was made under the constant temperature condition, and the planar optical waveguides of graded index profile have been fabricated. Mode indices of these waveguide samples have been measured with a symmetrio prism coupler at 632.8 laser wavelength. In this paper, white and Heidrioh's oalculational formulae determing the waveguide index profile by mode indices have been reduced, and simple new methods determing the waveguide surface index by mode indices have been presented.