Oxotitanium phthalocyanine (TiOPc) material is found to feature electrical bistability characteristics for the first time. A one-component organic memory device based on the sandwiched structure of TiOPc thin film is demonstrated in this paper. A high on–off ratio of four orders of magnitude and a large 4 V read voltage window have been achieved at room temperature, which can reduce readout errors induced by the dispersions of resistance parameter. The device exhibits no significant degradation of the retention performance in both high resistance and low resistance state after 1.4×104 s continuous reading. In addition, the switching mechanism of the device is also discussed by comparing and analyzing the current–voltage characteristics of Al/TiOPc/indium tin oxide/glass and Al/TiOPc/Si device.