Since the birth of Natural User Interface (NUI) concept, the NUI has become widely used. NUI-based applications have grown rapidly, particularly those using gestures, which have come to occupy a pivotal place in technology. The ever-popular Smartphone is one of the best examples. Recently, video conferencing has also begun adopting gesture-based NUIs with augmented reality (AR) technology. The NUI and AR have greatly enriched and facilitated human experience. In addition, path planning has been a popular topic in research area. Traditional path planning uses automatic navigation to solve problems, it cannot practically interact with people. Its algorithm calculates complexly, moreover, in certain extenuating circumstances, automatic real-time processing is much less efficient than human path modification. Therefore, considering such extenuating circumstances, we present a solution that employs NUI technology for 3D path modification in real time. In our proposed solution, users can manually operate and edit their own paths. The core method is based on 3D point detection to change paths. We did a simulation experiment about city path modification. Experiment resulted that computer can accurately identify a valid gesture. By using gesture it can effectively change the path. Among other applications, this solution can be used in virtual military maps and car navigation.