Abstract: Wireless sensor networks (WSNs), which are newly-emerging and application-oriented systems. Due to different requirements for the Quality of Service (QoS) imposed by different network services, QoS-supported WSNs, being characterized as “one-size-fits-all”, is the developing trend for the WSNs which provide multiple services, the improved routing protocol extends and improves the DD protocol for the data transmission of real-time services and best-effort services, so that a WSN can provide differentiated services (DiffServ). Experimental results obtained for the established simulation model show that the improved routing protocol satisfies the transmission requirements for multiple services and balances the energy consumption of the nodes in the whole network, with the network lifetime being prolonged.