To assess the feasibility of ultra-small GSH-protected Au nanoclusters (NCs) employed as X-ray computed  tomography (CT) contrast agent and study the effects of efficient uptake and clearance, CT values and time-dependent two- and three-dimensional images were recorded. The CT values of tumor region showed that the enhanced comparison gradually increased with the time. And the high enhanced comparison can also be reflected by distinct images until 6 h later. Therefore, high uptake of cancerous cell was proved by the CT values and two/three-images, which contributes to the application of Au NCs in tumor target imaging. High CT values of bladder were detected from the beginning, showing that Au NCs can permeate kidney tissue and be cleared by bladder. And the enhancement comparison of kidney revealed the possible application of exploration damage and lesion as probe.Cited