  Nonlinear evolution of circularly polarized Alfv\'en waves are discussed by
using the recently developed Vlasov-MHD code, which is a generalized
Landau-fluid model. The numerical results indicate that as far as the
nonlinearity in the system is not so large, the Vlasov-MHD model can validly
solve time evolution of the Alfv\'enic turbulence both in the linear and
nonlinear stages. The present Vlasov-MHD model is proper to discuss the solar
coronal heating and solar wind acceleration by Alfve\'n waves propagating from
the photosphere.
