In this paper the integer valued omega-index theory parameterized by all om
ega on the unit circle for paths in the symplectic group Sp(2n) is establis
hed. Based on this index theory, the Bott formula of the Maslov-type index
theory for iterated paths in Sp(2n) is estalished, the mean index for perio
dic solutions of Hamiltonian systems is defined, and the increasing estimat
e of the iterated Maslov-type index in terms of the mean index is proved.