  We present a study of molecular outflows using high-resolution mapping of the
CO (1-0) line emission toward eight relatively nearby 6.7 GHz methanol masers,
which are associated with massive star forming regions. Outflows were detected
in seven out of eight sources, and five of them clearly show bipolar or
multiple outflow morphologies. These outflows have typical masses of a few
solar masses, momenta of tens of $M_{\odot}$ km s$^{-1}$, kinetic energies of
$\sim$ 10$^{45}$ ergs, and the mass entrainment rate of a few $10^{-5}
M_{\odot}$ yr$^{-1}$. They have significantly more mass and kinetic energy than
their low-mass counterparts. In some of the sources, the massive outflow is
obviously associated with a particular massive star in the cluster, while in
others the origin remains uncertain. The high detection rate of outflows toward
methanol masers suggests that the outflow phase of massive protostars
encompasses the methanol maser phase.
