The purpose of this study was to determine the influence of muscle fatigue in elbow flexors on the sense of force reproduction. Fifteen healthy subjects were recruited for this study. Maximum voluntary force (MVF) of elbow flexor muscles was measured by a digital tensiometer. Force errors were measured to test accuracy of the sense of force reproduction in elbow flexors. The subject was required to flex the elbow joint, to maintain and concentrate on about 20% of the MVF target force under visual feedback for 3 seconds. After a 5 second period rest, the subject was asked to duplicate the target force actively. Muscle fatigue was evoked with isometric contraction of the elbow flexors. Isometric contraction was continued until a 50% drop in MVF. The difference, in kilogram between the target force and the reproduced force was calculated for measuring force error. Force errors were compared between the non-fatigued condition and the fatigued condition by the paired t-test. Force errors were significantly increased in the fatigued condition compare to non-fatigued condition. This result suggests that the sense of force reproduction can be disturbed by localized muscle fatigue.