We propose a novel Kinect-based robot-assisted ultrasound scanning system. The system is composed of a robotic arm, a linear ultrasound probe with marker, and a Kinect as a vision servo. The robot follows the navigation of the Kinect sensors and scans the legs automatically. A Kinect is chosen here to obtain the 3Dimages of legs and the probe. The probe and legs are segmented in RGB images and depth images in real time. The probe’s position and orientation are registered according to the registration. Then the pose of the robot can be calculated according to the calibration result of Kinect coordinate system and robot coordinate system. The robot holds the probe to scan the legs according to the planned path and current pose. Both phantom and human leg platforms with robot and ultrasound probe and Kinect are built up and scan experiments are carried out. The transformation matrixes between two legs, depth imaging, Kinect and ultrasound probe coordinate systems, are obtained. The distance between the probe and the scanned leg is calculated frame by frame to guarantee safe scanning without force sensors. Results from the initial experiments indicate that the idea is feasible and promising for its improved inspection efficiency. Clinically, the method can be implemented for pre-operative procedures and this may improve the ultrasound scanning effiency.