The introduction of Internet of Things (IOT) triggered a fever of IOT technology. Scholars are dedicating themselves in the research on relative technology of IOT so as to make contributions to the realization of an intelligent society. IOT technology has attracted great attentions from Chinese academic fields and news media. IOT related majors have been set up in universities so as to culture high-tech talents. Currently, problems still exist in IOT related concepts, principle analysis, designs for technology structure and IOT system model. Based on case study on IOT technology application, and see it from the perspective of the current study state, application and future development prospect, this paper introduces the key technology of IOT and its structure design. It also gives examples of its practical application. With the development and application of IOTï¼life could be more intelligent. For instance, city living environment will be more intelligent; real-time tracking dynamic information could be realized in logistics; congestions of large scale could be avoided with IOT application in traffic direction; timely medical assistance could be taken with the help of tele-medicine.