A detachable aromatic nebulizing diffuser includes a base panel, an electric fan, a fluid container, an ultrasonic oscillator, a power jack, a water baffle, a lower housing and a top cover. The ultrasonic oscillator oscillates ultrasonic waves to cause an aromatic fluid in the fluid container into a fine mist that is carried by currents of air caused by the electric fan and guided through an air duct in the fluid container. The fluid container has bottom mounting rods detachably plugged into respective tubular upright posts of the base panel, facilitating mounting and dismounting. The water baffle and the top cover are light transmissive for creating a visual effects upon working of a light source that is carried on the ultrasonic oscillator.