  We discuss the quantum Hall effect of bilayer graphene with finite gate
voltage where the Fermi energy exceeds the interlayer hopping energy. We
calculated magnetic susceptibility, diagonal and off-diagonal conductivities in
finite-magnetic-field formalism, and observed crossover of integer quantum Hall
effect from two independent monolayer type system to strongly coupled bilayer
systems by changing the ratio of interlayer hopping energy and the gate
voltage. We also discuss the case of multilayer systems with Bernal stacking
