Abstract: Many emerging mobile wireless applications for emergency and military situations depend upon secure group communications But group key management in mobile ad hoc networks faces a great challenge because of mobility, unreliable links, and multi hop communications Based on the threshold secret sharing mechanism and RSA encryption technique, a novel group key management framework named DGKMF （distributed group key management framework） is proposed in this paper, in which each entity holds a secret share and multiple entities in a local neighborhood can jointly update the group key Simulation results demonstrate that DGKMF is better than other algorithms and protocols such as CKD, GDH v 2 and BD in the group rekey success ratio and delay