A lattice Boltzmann model is developed to simulate melting with natural convection.In a lattice Boltzmann model for non-linear convection diffusion equations,an evolution equation of temperature distribution is constructed with selecting an equilibrium distribution function and a nonlinear source term properly.Thermal properties of solid phase and liquid phase are accomplished by using an adjustable relaxation time.Simulation results agree well with analytical solution and correlation in previous studies.It indicates that natural convection has importanct influence on total heat transfer,and heat conduction of solid phase affects total heat transfer,melting velocity and temperature distribution.