A system of measuring a line-of-sight of an observer including an user imaging unit which is wearable by an observer of an object in a display space and captures a field view image in front of the observer, an user measurement unit which is wearable by the observer and obtains line-of-sight measurement data showing a line-of-sight direction of the observer relative to a coordinate system of the field view image, and a line-of-sight measurement apparatus which obtains a gaze point of the observer based on a coordinate position where 3D shape data of the display space including the object intersect a vector of the line-of-sight direction of the observer.