Abstract: This paper proposes a protocol for wireless sensor and actor network based on weighted Voronoi diagram and degree-constrained minimum spanning tree (VDMST), considering residual energy balance of network nodes. Based on weighted Voronoi diagram, the protocol organizes network nodes to some clusters which include an actor and some sensors. The operation of VDMST protocol is divided into rounds and the degree-constrained minimum spanning trees are dynamically generated according to network states in each round. The simulation results show that VDMST protocol can improve the residual energy balance of network nodes and prolong network lifetime.