A new method od detecting pupil center position, eye gaze point and eye blinking is proposed for the author¡Çs developed Eye-Sensing Head-Mounted Display (ES-HMD), which is able to not only provide the userwith 3-d virtual image but also monitor the user¡Çs both eyes by using infra-red CCD cameras. A real-time eye gaze point and eye blink detection system called GAB-DES is developed based on the proposed method. Laboratory experiments for GAB-DES is conducted to evaluate the proposed methods. From the results of the experiment, it is confirmed that the proposed method of detecting pupil center posiotion and eye gaze point is more robust and accurate than by the previous method. Concerning the eye blink detection, the rate of detecting involuntary eye blink is 93.1% while the rate of detecting intentional eye close is 100%.