Abstract: Objective To explore the short-term outcome of unicompartmental knee arthroplasty (UKA) with 3D print positioning osteotomy guide plate in treatment of end-stage medial compartment osteoarthritis (MCOA). Methods From June, 2016 to October, 2016, 25 patients with MCOA were treated in our department. The patients were divided into 3D group and conventional group according to the different surgical methods. The operation time, volume of bleeding (Intraoperative volume of bleeding with postoperative drainage), postoperative tibial prosthesis deviation (the coronal angle between perpendicular line of tibial prosthesis and tibial mechanical axis) and postoperative 1, 3, 6 months HSS score were recorded and compared separately to evaluate the efficacy of UKA with 3D printing guild plate. Results All patients were followed up to 6-10 months (average of 8 months). The amount of bleeding, tibial prosthesis deviation in 3D group[(237.1±143.7)ml, 1.5±0.9] was superior to the conventional group[(391.2±163.8)ml, 2.9±1.6], the operation time between the two groups[3D group:(89.2±19.0)min, conventional group:(94.2±30.3)min] was no significant difference. The differences in HSS score before the operation, 1, 3 and 6 months after the operation in the same group compared to each other were statistically significant. The HSS score had developed in a good way over time. However, the differences of postoperative HSS score between the two groups at the same period were not significant (P>0.05). Conclusion UKA with 3D print positioning osteotomy guide plate in treatment of MCOA has a good short-term outcome with less bleeding, accurate osteotomy and individualized treatment.