In this study, we demonstrate a transistor-type ZnO nanowire (NW) memory device based on the surface defect states of a rough ZnO NW, which is obtained by introducing facile H2O2 solution treatment. The surface defect states of the ZnO NW are validated by photoluminescence characterization. A memory device based on the rough ZnO NW exhibits clearly separated bi-stable states (ON and OFF states). A significant current fluctuation does not exist during repetitive endurance cycling test. Stable memory retention characteristics are also achieved at a high temperature of 85 °C and at room temperature. The surface-treated ZnO NW device also exhibits dynamically well-responsive pulse switching under a sequential pulse test configuration, thereby indicating its potential practical memory applications. The simple chemical treatment strategy can be widely used for modulating the surface states of diverse low-dimensional materials.