Research on the thermal decomposition of manganese oxalate (MnC2O4) from manganese extraction product of Lampung manganeses ore on manganese oxide recovery has been carried out. This study consisted of three main stages, namely reductive leaching, precipitation of manganese using oxalic acid to produce manganese oxalate, and thermal decomposition to produce manganese oxide. In the thermal decomposition process, MnC2O4 as much 1 g and 3 g using decomposition time of 30 minutes, 1, 2, and 3 hours; and the temperatures of 350, 450, 550, and 650oC. Purity of manganese oxide from thermal decomposition is 96%. XRD analysis show a that at a mass of 1 g using a temperature of 350 dan 450 oC with variations time, manganese oxides phase is obtained hausmannite (Mn3O4) and bixbyite (Mn2O3). But at temperatures of 550 and 650 oC the hausmannite phase compound is completely transformed into bixbyite phase with highest peak intensity at an angle of 2θ = 33o. While using a mass of 3 g with all variations of time and temperature showed the acquisition of two types of manganese oxide phase, namely hausmannite and bixbyite.