  We perform the Hamiltonian analysis of general bimetric gravity. We determine
four first class constraints that are generators of the diagonal
diffeomorphism. We further analyze the remaining constraints and we present an
evidence that these constraints should be the second class constraints in order
to have theory with the Hamiltonian constraint as the first class constraint.
We also discuss the case of the non-linear bimetric gravity and argue that it
is very difficult to eliminate the ghost mode.
