Wireless Sensor Network (WSN) is becoming a more and more popular research area since its emergence. Many WSN researches rely on practical experiments in real wireless networks. However, to setup and conduct such an experiment is always cumbersome and time-consuming. So in this thesis, we design and implement a WSN testbed to solve the problem and help user focus on their researches. Our testbed provides necessary modules and service, such as command dissemination and feedback module, data logging and collection module, network programming module and time synchronization service. Different from other existing testbeds, our testbed removes wire connections and gateways, which are used for transmitting commands, feedbacks and users’ programs, between nodes so that it provides high flexibility in deployment and reduces costs. This testbed can be widely applied in different environments without extra devices but experimental motes. We have deployed our testbed on the 19th floor of EWI building at TU Delft and verified its functionality and performance with tests. The testbed meets our design goals that it can be used for most WSN experiments. We hope this testbed can make a contribution to WSN research in the future.