In order to solve the broadcast storm problem caused by blind flooding, a cross-layer dynamic probabilistic broadcasting strategy for mobile ad hoc networks (CLDPB) is proposed. CLDPB adopts the cross-layer design, which let routing layer share the received signal power information at MAC layer while still maintaining separation between the two layers. The additional transmission range that can benefit from rebroadcast is calculated according to the received signal power, which is applied to dynamically adjust the rebroadcast probability. CLDPB reduces the redundant retransmission and the chance of the contention and collision in the networks. Simulation results reveal that the CLDPB achieves better performance in terms of the saved-rebroadcast, the average packet drop fraction, the average number of collisions and average end-to-end delay, which is respectively compared with the blind flooding and fixed probabilistic flooding applied at the routing layer while IEEE 802.11 at the MAC layer.