A liquid perfume diffuser includes a perfume bottle (1) holding a liquid perfume, an inner cap (3) threaded onto the perfume bottle, a rotary cover (5) rotatably capped on the inner cap (3) for pressing and rotating by the user to move the inner cap (3) relative to the perfume bottle between a close position and an open position, so that when the perfume is opened, the liquid perfume can then be absorbed by a liquid-absorbing material (7) in the rotary cap, enabling the pleasant smell of the liquid perfume to be slowly and naturally released into the outside open air through a capillary effect.
