無線感測網路(wireless sensor networks)主要是由一到數個基地台(base station)和眾多感測器所組成的網路系統。現今已廣泛運用在各種不同環境中進行通訊、監測等應用。而感測器有傳輸距離上的限制，所以當感測器與基地台距離太遠時，就必須要透過其他感測器才能將感測到的資料轉傳到基地台。每個感測器都具有體積小、低成本、簡易計算及儲存能力、通訊能力等性質，並配有固定能源。由於感測器節點一經佈署後就無法更換電池，一旦電力耗盡，感測器即失去作用。因此在使用上便有了限制。 近年來，資料聚集在無線感測網路中變成一個很重要的研究議題。本論文提出一個以樹狀結構為主的資料聚集機制。在網路初始階段建立樹狀架構，並使用混合式參數來選擇傳輸路徑，且在每個週期內對網路中所有感測器節點所蒐集到的資料，透過資料聚集的動作去除重複冗餘的部分，以達到節省電量、延長網路生命周期的效果。 Wireless sensor networks (WSNs) are composed of one to several base stations and multiple sensor nodes, which are extensively used in many different kinds of environments currently, such as communication and monitoring. While the sensors have the limitation of transmission distance so that when the sensors are far away from the base station, they should relay the data to the base station through other sensors. Every sensor has the qualities that small, low-cost, the capacity of simple calculation, storage and communication, and it also equips the fixed energy. In recent years, data aggregation of the wireless sensor networks has become a very important issue in research. In this paper, We propose a Tree-based Data Aggregation Mechanism (TDAM) in wireless sensor networks. Building a tree structure in the initial phase of the network, and use the hybrid parameters to choose the transmission path, and remove the extra part of the data which are aggregated by all the sensor nodes in the network through the data aggregation in each round. Finally, it will achieve the effect that saving power and extending the lifetime of the network.