Abstract: The renormalization grop (RNG) based on the κ-ε turbulence model and the hybrid finite analytic method with staggered grids is used to calculate negatively buoyant jets in static ambient.The maximum penetration depth,velocity vector in the whole field,the temperature contours,the turbulent kinetic energy contours,the velocity and temperature distributions in cross sections and the axial temperature distribution are got by simulation.The calculated results are compared well with the available experimental date,which shows that the RNG based on the κ-ε turbulence model amd the hybrid finite analytic method can be used to simulate the variation density flow.