Motion tracking is a key area of sensor systems for security, transportation, and high-tech industry. In this work, a self-powered motion tracking system is developed to monitor moving speed, direction, acceleration, starting and ending positions, and even the moving path of a moving object. Such a system is based on a set of triboelectric nanogenerators (TENGs) that are composed of two friction layers with opposite triboelectric polarities (Kapton and Aluminum) and operates in the sliding mode. Velocities of a moving object are monitored from -0.1 m s(-1) to +0.1 m s(-1) at a step of 0.01 m s(-1), and accelerations from -0.1 m s(-2) to +0.1 m s(-2) at a step of 0.02 m s(-2). Furthermore, an 8 x 8 two-dimensional coordinates system with 16 groups of TENGs is created, and the moving path of an object is obtained. This study opens up a new area of TENGs as active sensors with great potential in self-powered systems, positioning detecting, motion tracking, environmental and infrastructure monitoring, and security.