A storage medium storing multimedia data for the reproduction of audio-visual (AV) data and a programming function, and a reproducing apparatus and method thereof. The storage medium includes: reproduction mode data for reproducing audio-visual (AV) data; program data including a plurality of program applications for providing interactive functions with a user and/or additional functions using the AV data; system data for controlling the execution of the reproduction mode data and the program data; and application objects for managing the execution of the program data and information on the reproduction mode data to be reproduced along with the execution of the program data. Accordingly, various user interfaces and/or various additional functions can be provided, as well as simple reproduction of AV data. Also the program application can be prevented from using malicious intent, and program applications having the same function can be reused without modification or recompilation.