無線感測網路(Wireless Sensor Networks)是由許多無線感測器(Wireless Sensor node)所組成，感應器主要是執行編譯好的完整程式流程。特性是低耗電、低成本、低頻寬、與低運算能力。為了讓使用者可以快速的設計一個無線感測網路程式，使用者需要一個專門為無 線感測器所設計的作業系統，其中提供了完整的硬體控制函式庫與作業控制流程。而現今主流的無線感測網路作業系統都設計的過於龐大，導致程式編譯之後檔案太過龐大，而難以放入低成本的處理器記憶體中。我們提出一個輕量級的無線感測網路作業系統來改善這個問題。透過適合的設計概念與程式碼的最佳化來達成輕量化的目標。由實驗結果證明，在同樣的演算法下，我們提供的作業系統大約可以節省兩萬位元組的大小，成功的達成輕量化的目的。 Most wireless sensor networks are composed of large numbers on tiny networked devices, which is called sensor node. Wireless sensor nodes are usually static-programmed, low-power, low-cost, low-bandwidth, and low-computation-power. To de sign a sensor network application, users and researchers need an operating system which is designed for the sensor nodes that provides a complete hardware control library and control scheme to the sensor node hardware. Nowadays most popular sensor operating systems are being composed to be very lager and complex, and most sensor applications just need a few functions and variables to realize the developed scheme from users and researchers. In this thesis, we address the above problem by design a ightweight operating system for wireless sensor networks, LOS. LOS is designed to be a simple and lightweight operating system for wireless sensor nodes. By implement applications of the same kind on different operating systems, showed that the whole code size will be efficiently reduced in LOS.