Renal artery occlusion is an unavoidable process during operations such as nephrectomy, carcinoma resection, kidney transplantation and so on. For minimizing the kidney injury, the optimal renal ischemia time was experimentally investigated. Optical coherence tomography (OCT) is a high resolution imaging modality can non-invasively image biotissue in vivo and in real time. In order to study the relationship between tubular injury and the renal ischemia time, OCT images of Wistar rat kidneys endured various ischemia time were obtained throughout the whole ischemia-reperfusion procedure. The tubular density and the average diameter of uriniferous tubules were considered as biomarker of kidney activity, and the quantitative results well described the degree of kidney injury.