Abstract: A 13-speed lattice Boltzmann model is used to investigate Couette flow with a temperature gradient and viscous cavity flow. The Couette flow for Pr=0.91, Re=100,5000 and Pr=0.91,1,1.25 and Re=3000, are simulated with the evolution of driven flow, temperature and viscous heat dissipation. And the distributions of vortex and temperature are shown at Re=3000 the steady flow field for viscous cavity flow.