Objective To compare the differences between volar and dorsal plate positions in the treatment of unstable fracture of distal radius. Methods From June 2000 to December 2006, 61 cases with fracture of distal radius weretreated, 27 males and 34 females aged 22-70 years (55.5 years on average), among which 18 cases were caused by traffic accidents and 43 cases falls. All cases were fresh closed fractures. All patients had AP and lateral X-ray films of the wrist preoperatively and 30 cases experienced CT scan. According to AO, there were 25 cases for B1, 18 for B2, 7 for B3, 7 for C1, and 4 for C2. All the cases were randomized into 2 groups: the wrist palmar group (group A, n=34) and dorsal group (group B, n=27), to perform volar and dorsal plate fixation, respectively. As to the measurement of fortune for the preoperative ruler and incl ination angle, group A were (—45.0 ± 53.0)º and (8.6 ± 3.1)º, respectively, and group B were (—40.0 ± 30.0)º and (7.3 ± 5.6)º, respectively. Preoperative radial shortened (12.0 ± 5.3) mm in group A, and (10.3 ± 4.2) mm in group B. Joint surface level was (4.3 ± 2.2) mm in group A, and (4.1 ± 3.3) mm in group B. Results All of the 61 cases were followed up for 6-27 months (16 months on verage). All the fractures were healed, the time to heal ing in group A was (8.2 ± 1.6) weeks, and in group B was (8.1 ± 1.2) weeks, and the difference was not significant (P gt; 0.05). As for the wrist function by Cartland-Werley scoring at the 8th week after operation, 7 cases were excellent, 10 good, and 17 poor in group A with the choiceness rate of 50.0%, while 7 cases were excellent, 11 good and 9 poor in group B with the choiceness rate of 66.7%. There was significant difference between the two groups (P lt; 0.01). And at the 24th week after operation, 21 cases were excellent, 9 good, and 4 poor in group A with the choiceness rate of 88.2%, while 18 cases were excellent, 5 good, and 4 poor in group B with the choiceness rate of 85.2%. There was no significant difference between the two groups (P gt; 0.05). As for radiological assessment by Sarmiento, device and palm incl ination angles in group A were (9.5 ± 3.1)º and (18.0 ± 8.2)º, respectively, and in group B were (11.0 ± 4.7) º and (16.0 ± 7.6)º, respectively. No radial shortening was found either in group A or in group B, and joint surface level in both groups were less than 1 mm. There was no significant difference between group A and group B in terms of all indicators postoperatively (P gt; 0.05), but there was significant difference when compared with preoperation (P lt; 0.001). With regard to comparison of postoperative compl ications between the two groups, there was no significant difference (P gt; 0.05) in early postoperative compl ications, but there was in long-term compl ications (P lt; 0.01). Conclusion The volar and dorsal plate positions may offer effective stabil ity for unstable distal radial fracture and early functional exercise. The volar plate position may influence the pronation function of the wris joint in the short run, while the dorsal plate position may cause more compl ications in the long run.