  We show relations between superposition of macroscopically distinct states
and entanglement. These relations lead to the important conclusion that if a
state contains superposition of macroscopically distinct states, the state also
contains large multipartite entanglement in terms of several measures. Such
multipartite entanglement property also suggests that if a state contains
superposition of macroscopically distinct states, a measurement on a single
particle drastically changes the state of macroscopically many other particles,
as in the case of the N-qubit GHZ state.
