Abstract: he laser refractivity of KH₂PO₄, KD₂PO₄, NH₄H₂PO₄ solutions and H₂O, D₂O have been studied in detail by abbe refractometer. The temperature coefficients of their refractive indices and the dispersive power to laser and natrium light, have been accurately measured. The relationship between different concentrations of the solutions and the refractive index are determined. The refractive regularities of some saturated solutions are presented separately. Using the laser-fringe method, the saturated data of the corresponding .solution are also determined precisely. The refractive indices of these medium to He-Ne laser are less than those to natrium light. The refractive indices of D₂O are less than those of H₂O. The refractive indices of the solutions increase linearly with the increasing of the concentration. The higher the concentration of the solution, the stronger the dispersive power of the refractive index. As for the solution with definite concentration, the refractive index decreases linearly as the temperature rises. The temperature coeffcients of the refractive indices of these mediums range from 0.00010 to 0.00016.

Key words: Phosphatic solutions, Refractive regulations, Laser