Abstract: In this paper the symmetric instability is investigated analytically by use of Green's function method and Fourier analysis, Ageostrophic and nonhydrostatic Boussinesq equations with the feedback of condensation heating, which is calculated by the wave-CISK parameterized model (Emanuel 1982),are used in the investigation. The analytic expressions of stream functions for any heating profiles with symmetric instability are obtained and so is their relation of dispersion. A number of specified heating profiles are assumed and discussed.