Provided is an apparatus and method of modifying a user interface based on a network condition. The apparatus includes a communication unit, a contents replaying unit, a determination unit, and an interface modification unit. The communication unit communicates with a server through one or more wired/wireless communication methods. The contents replaying unit provides a user interface screen for selecting contents and replaying contents selected by the user. The determination unit determines whether or not network connect with the server is necessary for the replaying of the contents displayed on the user interface screen for selecting the contents. The interface modification unit modifies the user interface screen for selecting the contents according to whether or not the network connection is necessary.