  In present paper, from the viewpoint of physical intuition we introduce a
Hamiltonian system with multiscale rotation, which describes many systems, for
example, the forced pendulum with fast rotation, weakly coupled $N$-oscillators
with quasiperiodic force and so on. We study the persistence of invariant tori
for this Hamiltonian system, and establish some KAM type results including the
isoenergetic type. As consequences, we can show that Boltzmann's ergodicity
hypothesis is also not true for this Hamiltonian system.
