We present a scheme for realizing probabilistic teleportation of an unknown N-atom state via cavity QED.This scheme requires only a noumaximally entangled pair to be used as a quantum channel.so the requirement of entanglement is reduced.In addition,our scheme does not involve the Bell-state measurement and is insensitive to the cavity decay,which is important from the experimental point of view.If the quantum channel is a two-atom maximally entangled state,teleportation of an unknown N-atom state can be realized by a simpler scheme via cavity QED.