Abstract: In order to meet the needs of vehicle driver drowsiness detection system, A driving drowsiness detection system for mobile phone is designed by using the front camera of the phone. The Haar-like feature and Adaboost classifier are used to detect the driver’s face, and then, same method is used for a rough eye detection. Next, Otsu binarization is combined with gray projection to calculate the accurate eye height and evaluate the statues of eyes. Finally, a method according to the PERCLOS is used to evaluate the degree of drowsiness. Experimental results show that the system has a high accuracy, and it can adapt to the changes of light. So it can be effectively applied to the driver’s drowsiness detection.