The present invention relates to a mobile communication terminal and operating method thereof in which data sync error occurring when multimedia data is played can be compensated for. The mobile communication terminal includes a speaker through which played multimedia data is output, a display unit on which text data are output, an multimedia controller that analyzes and plays multimedia data, compensates for error of an output time, which is generated as the multimedia data are played, and outputs compensated text data, and a controller that manages data when multimedia data is played, and controls the driving of the speaker and the display unit. Temporal error between output time information and an audio signal that is actually output, and proportional temporal error occurring in proportion to an output time are calculated. Temporal information is compensated for based on the calculated temporal error and proportional temporal error.