Provided are a system and method for simultaneously reconstructing an initial three-dimensional (3D) trajectory and velocity of an object by using single camera images. The system for simultaneously reconstructing an initial 3D trajectory and velocity of an object by using single camera images includes a receiver configured to receive 3D world coordinate information of a starting point of an object and object-captured image information of a single camera, a two-dimensional (2D) coordinate acquisition unit configured to acquire 2D image coordinates of the object from the object-captured image information, and a reconstructor configured to simultaneously reconstruct an initial 3D velocity and trajectory of the object by applying a 3D motion equation to the 2D image coordinates and depth information from the single camera to the object.