The authors describe a real-time 3D computer vision system called MIMIC (Motion Interface & Motion Information Capture system) that can capture and save the motion of an actor. This system analyzes input images from vision sensors and searches feature information like a head, hands, and feet. Moreover, this estimates intermediated joints as an elbow and knee using feature information and makes a 3D human model having 20 joints. This virtual human model mimics the motion of an actor in realtime. Therefore this system can realize the movement of an actor unaffectedly because of making intermediated joint for complete human body contrary to other marker-free motion capture systems.