In statistical theory of Magnetohydrodynamic (MHD)
turbulence, the quantities of major interest are energy spectrum and
energy flux.  Current high resolution computer simulations show that
the energy spectrum of turbulent magnetic fluid is Kolmogorov-like.
We apply self-consistent renormalization group (RG) to MHD equations,
and show that viscosity and resistivity get renormalized,
and that the Kolmogorov's k^{-5/3} energy spectrum is a
consistent solution of RG equations.  We have successfully used renormalized
parameters to do large-eddy simulations of MHD turbulence.

There are various kinds of energy transfer rates among Fourier modes
of velocity ( u) and magnetic  b fields.
They are  u to  u,  u to b,  b to  u, and  b to  b.
We have computed the above quantities numerically and
analytically (field theoretic), and found them to be in close
agreement.  Important conclusions from these results are: forward
cascade of magnetic energy, and significant energy transfer from
large-scale velocity field to large-scale magnetic field.  We believe
the later flux plays a major role in the amplification of magnetic
field (dynamo effect).  The effect of magnetic and kinetic helicities
have also been explored.