In this paper,by introducing the concept of the natural interaction which is the latest achievement in thehuman-computer interaction research and based on the powerful capabilities of the Kinect sensor to identify humanbody parts and to track the joint space motion as well as to position the joint coordinates,a method to adopt the motionsensing-based human-computer interaction technique to carry out the geometric design of highway alignments ina three-dimensional virtual space is put forward,and a system framework of the true three-dimensional highway designis established.Then,the process of adopting gestures to design highways is discussed.Moreover,the paperdescribes the functional design of functional modules and the relationships among these modules,which includes thegesture recognition,the perspective control,the real-time dynamic interactive alignment optimization,etc.Finally,with Microsoft's SDK and Google Earth as the third-party software,a system prototype is developed and the correspondingexperiments are performed,thus realizing the goal of transforming the two-dimensional nature of both thehuman-computer interaction and the highway design platform into the three-dimensional nature,and the feasibilityof the proposed method is accordingly verified.