This study aims to analyze muscle synergies in darts throwing movement to clarify how the central nervous system (CNS) controls muscle activation to produce complicated motion. Activities of 10 different muscles on upper limb were recorded through surface electromyography (EMG) electrodes from four participants with less experience of dart throwing. Subsequently, non-negative matrix factorization (NNMF) was applied to the collected EMG signals for muscle synergy analysis. Results showed that three muscle synergies could explain sufficiently the observed EMG data, with determination coefficient r2 = 0.91 ± 0.02 across four subjects. However, it was found that there was significant difference in terms of patterns of both muscle synergies and activation coefficients between participants, which might reflect different neuromuscular control strategies in dart throwing.