A locking doorknob recognizes a fingerprint, in which the detecting sensor of a fingerprint is installed on the spot of the doorknob that a thumb or other fingers are placed naturally as the door is being opened. The locking doorknob is an electro-mechanical device which can be powered by a remote electrical power system, specifically by electromagnetic induction through the door latch and strike plate. During operation, as soon as a user grasps the doorknob, a fingerprint is measured and searched, and if the fingerprint corresponds to a fingerprint previously input, the door is unlocked and the doorknob can be turned to open the door. In this way, fingerprint recognition and opening of the door are performed at the same time.