A cup assembly includes a cup (10) and a lid (20) to define therebetween a first passage and a second passage to allow a liquid cooling compartment between the lid (20) and the cup (10) to be filled with liquid contained in the cup when the first passage is clear and the second passage is blocked and the liquid in the liquid cooling compartment is able to flow out of an outlet (23) in communication with the liquid cooling compartment when the second passage is clear and the first passage is blocked.