【Abstract】 Objective To investigate the effect of the volar capsular l igament complex on stabil ity of the wrist jointand to provide basic biomechanical theoretical criteria for cl inic appl ication of the external fixator. Methods Nine upperl imbs specimens (left 6, right 3) were taken from fresh adult cadavers to make wrist joint-bone capsular l igament complex specimens. Firstly, soft tissues of forearms and hands were resected and capsular membranes and l igaments were reserved to make the bone-articular l igament complex (normal specimen). Secondly, the volar capsular l igament complex was cut off from radial malleolus to ulnar malleolus (impaired specimen). Thirdly, the impaired volar capsular l igament complex was interruptedly sutured by the use of 4# suture silk (repaired specimen). To simulate cl inical operation with external fixator, the biomechanical test was done according to the sequence (normal, impaired, repaired, repaired and fixed, impaired and fixed). Statistical significance was analyzed through selected loads at the three different shifts (1.5, 2.0, 2.5 cm). Results According to the sequence (normal, impaired, repaired, repaired and fixed, impaired and fixed), when the shift was 1.5 cm, the different respective loads were (60.74 ± 20.60), (35.23 ± 13.88), (44.36 ± 20.78), (168.40 ± 29.21) and (139.00 ± 33.18) N, respectively. When the shift was 2.0 cm, the different loads were (138.46 ± 12.93), (87.17 ± 24.22), (97.52 ± 23.29), (289.00 ± 54.29) and (257.98 ± 55.74) N, respectively. When the shift was 2.5 cm, the different loads were (312.87 ± 37.15), (198.16 ± 37.14), (225.66 ± 30.96), (543.15 ± 74.33) and (450.35 ± 29.38) N, respectively. There was no statistically significant difference between the impaired and repaired specimens (P gt; 0.05). Similarly, there was statistically significant difference among the rest specimens (P lt; 0.05). The same statistical results were obtained when the two different shifts were compared. There was statistically significant difference at the three different shifts for the same specimen (P lt; 0.05). Conclusion Volar capsular l igament complex is an important anatomic structure to keep stabil ity of the wrist joint. The carpal instabil ity arises out of the injured complex. Repairing the injured complex only can not immediately restore stabil ity of the wrist joint. The external fixator can effectively help to diminish the relative shift of the impaired capsular l igament complex, to reduce the load of the repaired complex and to protect the complex accordingly. The device plays an important role in maintaining stabil ity of the wrist joint.