Abstract: To provide theoretical basis for investigating pathologic mechanism, we observed the effects of aristolochic acidⅠ（AAⅠ）on kidney fine structures and physiological index of mice to preliminary interpret the damage of AAⅠon kidney. Male Kunming mice（20 g±0.2 g）were divided into four groups, randomly. The experimental groups were intragastricly administrated with low, moderate, and high concentration of AAⅠ solution, and the control group with equal-volume water. After 30 days, we examined pathological changes of kidney, and measured correlated physiological index in blood and urine The results showed that with the increasing doses, mice body weights lowered obviously, urinary volumes increased in the initial stage, and then hypourocrinia, anuria, renal glycosuria occurred. While the TGF-β1 contents in serum went up gradually, and erythrocytes, hemoglobins, monocytes decreased. Compared with the control group, in cortex parts and the boundary between cortex and medulla parts, epithelial cells of proximal convoluted tubules damaged, and fibration penetrated deeply with the increasing doses from cortex to medulla parts. At the same time, we found that cell organs harmed and nuclei varied in electron microscope. The results showed that AAⅠ could damage kidney dose-dependently, lead mostly to pathological changes of renal tubule mesenchymal, and affect its normal fine structures.