A markerless three-dimensional object tracking method according to an embodiment of the present invention comprises the steps of: extracting feature points from a first image which is generated by a stereo camera calculating three-dimensional coordinates of the feature points and matching coordinate systems of the first image and a second image, which is a three-dimensional reference image, with each other such that the images are matched with each other. An objective of the present invention is to reduce time and cost needed for a matching process and provide an accurate surgery position for a doctor.COPYRIGHT KIPO 2016발명의 실시예에 따른 마커리스 3차원 객체추적 방법은 스테레오 카메라로부터 생성된 제1영상에서 특징점을 추출하는 단계 상기 특징점의 3차원 좌표를 계산하는 단계 및 상기 제1 영상과 3차원 기준영상인 제2영상의 좌표계를 일치시켜 영상을 정합하는 단계를 포함한다.
