We investigate the resistive memory switching behaviors of Yb 2O 3 thin films for different Ti-dopant concentrations. A higher doping concentration of 9.4% of Ti atom into Yb 2O 3 thin film causes the switching mechanism to change from bipolar to unipolar behavior. This is ascribed to different chemical compositions of the filament through the oxide film. The reset mechanism is associated with the annihilation of oxygen vacancies and other ionic and electronic defects within or near the interface area of oxide film for bipolar switching, while it is believed to be due to rupture of the conducting filament by local Joule heating effect for unipolar resistive switching. Furthermore, the incorporation of Ti atom into the Yb 2O 3 memory device exhibits improved electrical performances including low set/reset voltages and good endurance and retention characteristics.