Two-dimensional natural convection in water with density inversion is studied numerically in a rectangular cavity. The non-Boussinesq parabolic density-temperature relationship is incorporated in a finite element model. Numerical results are obtained for Rayleigh numbers up to 10 6. The evolution of the temperature field and flow pattern show that density inversion and initial location of the maximum density surface within the liquid have a determining effect on convection character. The investigation of aspect ratio on flow character is also presented. It is found that interactive convection across the density inversion surface is dependent on aspect ratio and Rayleigh number.