Abstract: Considering the features of mobile Ad Hoc networks such as lack of center nodes, multi-hops routing and limited resources, a hybrid checkpointing strategy combining synchronous checkpointing and asynchronous checkpointing is suggested for clustering-based Ad Hoc networks. Namely, the checkpoints in the same cluster must keep synchronous, while the checkpoints in different clusters are independent. Firstly, a hybrid checkpointing model and its correctness criteria are discussed. Then, the elimination rules of different kinds of checkpoints are suggested based on the intra-cluster and inter-cluster checkpoint dependency graphs. Finally, the algorithms of checkpointing and rollback recovery are given, and the correctness of recovery is proved. The proposed strategy can not only avoid resource waste due to cascading rollback among the processes in the same clusters, but also avoid too much message transmission among the processes in different clusters, to reduce the wireless communication delay largely. Experiment results show that, comparing with the pure synchronous and pure asynchronous checkpointing methods, the proposed hybrid checkpointing strategy is a flexible and good trade-off scheme taking all kinds of resource constraints of Ad Hoc networks into account, and has the advantages such as short recovery time, less dependence on cluster heads.