Objective To compare the clinical efficacy of Oxford unicompartmentknee replacement （UKR）and total knee arthroplasty（TKA）in the treatment of medial knee osteoarthritis. Methods A total of 100 patients with medial knee osteoarthritis who underwent UKR and TKA from June 2015 to June 2019 in the first department of orthopedics and orthopedics，Dongzhimen Hospital from June 2015 to June 2019 were selected and divided into single condyle group and total knee group，with 50 cases in each group. Intraoperative blood loss，post⁃ operative total drainage volume，operation time and hospital stay，knee flexion，visual analogue scale（VAS）， American hospital for Special Surgery knee score（HSS）and the incidence of related complications were compared between the two groups. Results Less intraoperative blood loss and postoperative total drainage volume in single condyle group were found and the operation time and hospitalization time were shorter than those in the total knee group，indicating statistical significance（P < 0.05）. Knee flexion and HSS score of single condyle group were higher than those of the total knee group from 1 week to 1 year after operation，but VAS score was lower and the differ⁃ ence was statistically significant（P < 0.05）. The excellent rate of clinical effect in single condyle group from 1 week to 6 months after the operation was higher in single condyle group（P < 0.05）but no statistical difference wasfound 1 year after the operation（P > 0.05）. There was no significant difference in the incidence of postoperative complications between the two groups（P < 0.05）. Conclusion TKA and UKR are feasible treatment for medial knee osteoarthritis. UKR has a better effect on pain relief and knee function recovery within 1 week to 1 year after operation.