An essential oil diffusor assembly is disclosed. The diffusor assembly comprises a top cap having an opening, a diffusing member having a housing tip which is protruded out the opening of the top cap in order to prevent an essential oil from leaking out an inner surface of the top cap, an O-ring fastened on a bottom of the diffusing member, an air pump having a outlet for blowing out an air, a base, a flexible pipe attached to the outlet of the air pump and fixed on one top surface of the base, an oil reservoir having a holding bar formed on a bottom of the oil reservoir, wherein there exists a slender hole inside the holding bar so that the air pump is activated to let the air be supplied to the oil reservoir attached by the flexible pipe through the outlet of the air pump and the holding bar, a plurality of lighting elements disposed on the top surface of the base for emitting rays on the top cap and the oil reservoir in order to obtain good visual effects, a foam surrounding the air pump for absorbing a vibration and a noise, a mat disposed on a bottom of the air pump for absorbing a vibration and a noise, and a lower lid closing the bottom of the base, wherein the foam and the air pump are affixed on the lower lid and the diffusing member is sealed with the opening of the oil reservoir through the O-ring.