Abstract: Wireless sensor and actor networks (WSANs) are composed of sensors and actors to perform distributed sensing and acting tasks. Depending on the application of automation there may be a need to rapidly respond to sensor input. The issue of real-time communication is one of the most important challenges in wireless sensor and actor networks. Besides, the energy efficiency of network is also crucial. Although WSAN is derived from wireless sensor networks (WSNs), since the application requirements impose stricter constraints, many protocols and algorithms which have been proposed for WSNs may not be well-suited for the unique features and requirements of WSANs. A system model according to a real network situation is proposed. In this paper, the performance of clustering algorithms and a power control scheme in minimizing the network latency are studied, and a real-time energy-aware cluster-based routing protocol (RECRP) for WSANs is proposed and evaluated. A novel two-level clustering scheme based on power control technique is proposed in the algorithm to reduce the network latency, and cluster-heads are elected by an energy-efficient algorithm to increase the network lifetime. The experimental results demonstrate that the cluster could be formed stably by RECRP in WSANs, and it provides shorter latency and longer lifetime than the current typical routing protocols.