The continuous advance of the policy about ‘Energy saving and emission reduction’, along with the continuous development of information technology, control technology, which bring profitable conditions for the monitoring and control over the building (here mainly refers to the large building of government, commercial or industrial user). In particular, a interaction and monitoring system is proposed, which is used to monitor the parameters about energy consumption of energy consumption system or equipment inside the building, in addition the information about the running of the energy consumption system or equipment. At the same time, the relevant units of the energy consumption system or equipment is controlled by the interaction and monitoring system. The interaction and monitoring system for energy saving in building consists of the node for energy saving and monitoring, wireless sensor network (hereinafter referred to as WSN), the platform for energy saving and monitoring, making up the three-layer structure of the interaction and monitoring system inside the building. The node for energy saving and monitoring is a wireless sensor actually, which plays the role as collecting data and controlling. Along with the other nodes for energy saving and monitoring, as well as the nodes acting as repeater, router, coordinator, all nodes inside the building compose the WSN. The node acting as the repeater is of great significance for the transmission of data, especially when some nodes for energy saving and monitoring is located in underground building and some other places where the signal of WSN is blocked, as well as the places far away from the neighbor nodes of WSN. The coordinator is located on the platform for energy saving and monitoring, meanwhile the function of gateway is integrated in the node acting as the coordinator. This node converge the data of the WSN, and transfers the data to the server of the platform for energy saving and monitoring.