  In this paper, we investigate the pointwise behavior of the solution for the
compressible Navier-Stokes equations with mixed boundary condition in half
space. Our results show that the leading order of Green's function for the
linear system in half space are heat kernels propagating with sound speed in
two opposite directions and reflected heat kernel (due to the boundary effect)
propagating with positive sound speed. With the strong wave interactions, the
nonlinear analysis exhibits the rich wave structure: the diffusion waves
interact with each other and consequently, the solution decays with algebraic
rate.
