Abstract: It is assumed that the convective pattern in the bulk of outer core consists of buoyant parcels which rise to the top,forcing a broad descending flow in the bulk of the outer core.This convective circulation is sufficiently rapid that the outer core is close to a well-mixed adiabatic state.The small deviations from reference state results from the disturbance.With this convective model,it is studied the equation of parameters in the bulk of the outer core such as the radial variation of composition,the thermal deviation and pressure deviation.An equation of the vertical velocity was presented in order to calculate these parameters above and the strength of the stratification of the descending portions of the outer core was studied,which would be of importance to understand the radial variation of these parameters.