Abstract: In mobile Ad hoc networks, routing security has become an important issue due to the self-organize, dynamic topology and wireless surrounding of networks. Of all the current routing protocols, many take into account routing security under the assumption of existing security association while some use the expensive public key mechanism. These protocols cannot deal with attacks efficiently. This paper proposes an efficient and secure routing approach for ad hoc network, specify its routing process, analyzes its security performance and network performance, and compared it with the existent protocols .The new approach can solve security problems such as fabrication, modification, routing replay attack in mobile Ad hoc networks. And it also considered the resources are constrained in ad hoc network.