[ Objective ] To compare the clinical effect of open reduction and internal fixation(ORIF)through the lateral elbow approach versus the posterior transolecranon approach for treatment of Dubberley typeII-IIIB-type capitellum fractures. [ Methods ] A retrospective study was conducted on 39 patients who underwent surgical treatment in our hospital from December 2014 to December 2019 for Dubberley II-IIIB-Type capitellum fractures,which were classified according to the results of doctor-patient communication .Of them ,21 patients had operation performed through the lateral elbow approach(the lateral group),while the remaining 18 patients received surgery through the posterior transolecranon approach(the transolecranon group).The two groups were compared regarding to perioperative,follow-up and imaging data.[Results]All the 39 patients successfully completed the surgical treatment without serious neurological and vascular complications. All patients were followed up for more than 12 monthsThe lateral group was significantly superior to the transolecranon group in terms of surgical incision length, operation time,and blood loss,which was statistically significant (P<0.05).And there was no significant difference in hospital stay (P>0.05).The transolecranon group was significantly greater than the lateral group in terms of intraoperative fluoroscopy time and active activity time(P<0.05).The transolecranon group resumed full weight-bearing activity significant earlier than the lateral group(P<0.05). With the passage of time after operation, the VAS scores of 39 patients decreased significantly, while the elbow range of motion(ROM) and MEPS scores increased significantly(P<0.05). One month after operation, the The transolecranon group was significantly superior to the transolecranon group in terms of VAS score, MEPS score and ROM,and the differences were statistically significant (P<0.05).At the follow-up visit,there was no significant difference in VAS score, MEPS score and ROM(P>0.05).With respect to imaging evaluation, the fracture healing time of the transolecranon group was significantly earlier than that of the lateral group(P<0.05).The excellent and good rate of reduction was 15/21 (71.43%) in the lateral group and 17/18 (94.44%) in the transolecranon group.,which was statistically significant(P<0.05). [Conclusion] Although there are disadvantages in terms of operation time, surgical incision length and intraoperative blood loss, the posterior transolecranon approach has better clinical efficacy.