A convective turbulence system with a liquid medium (water or ethanol) that can be used for simulation tubulent atmospher for wavefront distortion compensation is described. After using the improved plate heater and cooler, a convective turbulence with wide intertial range similar to the spectra of atmospheric turbulence was obtained. Its turbulent intensity can be easily controlled and the optical characteristics of turbulence, such as stability, statistucs feature of turbulent and index of refraction fluctuation spectrum are better than that in the real atmosphere and can be repeated easy. So the system can be used for the experiments of adaptive optical compensation and for studying the interaction of turbulent and blooming, and light propagation through turbulent atmosphere.