An aroma-diffusing night lamp assembly includes a body holding a coupling socket at the top, a lamp bulb inserted into the coupling socket and electrically connected to the body, a lampshade defining a bottom coupling hole coupled to the coupling socket and a top opening for holding an aroma capsule, and an aroma capsule including a disposable heat-transfer container mounted in the top opening of the lampshade and an aromatic substance contained in the disposable heat-transfer container and heatable by the radiating heat energy of the lamp bulb to release an aromatic smell.