A muscular energy state analysis system and method for a swing motion and a computer program product thereof are provided. The system includes: a swing implement, for a user to perform the swing motion, and including an acceleration sensor for sensing acceleration of the swing implement when the swing implement is swung, so as to generate a swing speed data; a plurality of signal detection modules, for detecting electromyographic (EMG) signals generated by a muscles of the user; a database, for storing a muscular energy sample value,; a muscular energy analysis module, for analyzing the EMG signals and the swing speed data so as to obtain a plurality of muscular performance values; and a comparison module, for comparing the swing speed data and the muscular performance values with the at least one muscular energy sample value in the database, so as to generate a comparison result data.