A method and apparatus for reproducing audio/visual data in an Enhanced Navigation mode, and an information storage medium thereof. The information storage medium stores audio/visual data, and at least one Enhanced Navigation application including at least one Enhanced Navigation file, the Enhanced Navigation file being reproduced together with the audio/visual data, wherein the Enhanced Navigation application includes a loading information file, which includes preload information specifying the location of the Enhanced Navigation file to be buffered before reproduction of the Enhanced Navigation application, as the Enhanced Navigation file. Accordingly, it is possible to guarantee seamless reproduction of audio/visual data for an Enhanced Navigation application.