A circumaural earphone adapted to be worn on a head of a user is provided. The circumaural earphone includes a main frame, two adjusting modules and two earphone cups. The two adjusting modules are connected to two opposite ends of the main frame respectively. The two earphone cups are connected to the two adjusting modules respectively. Each of the adjusting modules is rotated to drive the corresponding earphone cup to move close to or away from the head of the user so as to adjust a clamping force applied to the head of the user by the two earphone cups.