Presented is a progressive investigation on the EEG of Han Chinese patients with Alzheimer's disease (AD).Thus, an investigative project on Q-EEG was performed on the ethnic Han Chinese patients with AD by the Neural Engineering Lab of Tianjin University. This project was intended to contribute to the knowledge of EEG changes specific to AD in comparison with that to normal aging in the ethnic Han groups of China. With this aim, resting EEG was recorded from a large group of recruited volunteers including these two kinds of subjects. As normal elderly people, we mean people who could be age-matched with AD patients and who did not present any cognitive impairment or any potential condition altering the EEG profile. Our present studies were undertaken to examine the background activity of EEG in AD with three different entropy definitions: information entropy, mutual entropy, and approximate entropy (ApEn). The progress achieved in this project is expected to provide fruitful clues about local neuropathology of AD.