Ag-ZnO-Ag X-ray detectors based on ZnO film and nanowires are both fabricated in this paper. Results of continuous X-ray radiation measurement show that the two detectors have high responsivity: the responsivity of the ZnO film device is about 0.12 μC/Gy under a 100 V bias voltage, and that of the ZnO nanowires device is about 0.15 μC/Gy under a 50 V bias voltage. Surface effect due to the absorption and desorption of oxygen on the ZnO surface, which makes the carrier lifetime increase, is decisive to the h...