Abstract: Aimed to monitor the forest micro-meteorology, the wireless sensor networks (WSN) system was researched and implemented in this paper. This system was deployed in the Jiufeng National Forest Park of Beijing Forestry University with 42 sensor nodes, covering an area of 5 990 m2, and the maximum height difference between nodes reached about 25 meters. To solve the problems of poor communication quality and packet loss caused by tree blocking in the forest environment, we had deployed nodes using a zigzag plan and proposed a reliable routing protocol and a congestion control mechanism for data transmission. Scalar data and picture data will be sensed by WSN and all these data were finally converged to the base station by a multi-hop network. A web client was built to check sensed data and configure network parameters remotely. The system had been run continuously for one year and 0. 2 million records had been accumulated for further analysis of forest micro-meteorology.