Abstract Atmospheric refraction index is one of the primary problems in theoretical atmospheric refraction research.A theoretical formula of the relationship between atmospheric refraction index and meteorological parameters was presented，based on the consideration for the influence of quadratic term in the ratio of the pressure and temperature on refractive index.The result indicates that it has to consider present precision measurement range.Moreover，according to electromagnetic medium dispersion theory，a theoretical model of group and phase refraction index with wavelength change，which could be transformed reciprocally for the same or different band was proposed.That means that it is feasibe to study atmospheric refraction delay in radio waveban using boptical astronomical observation
