Abstract:The expression of AQP1, 2 in kidney of filial Meriones meridianus was investigated by immunohistochemistry combined with stereological method, and the expression intensity of AQP1, 2 was analyzed by IPP professional image analysis software. Results showed that there was expression of AQP1, 2 in kidney of filial M.meridianus at postnatal day 1, 7, 14, 21, and 32. AQP1 immunopositive cells mainly distributed in the epithelial cells of proximal convoluted tubule and thin segment of medullary loop in kidney at postnatal day 1, 7, 14, 21, and 32,while AQP2 expressed on the apical plasma membrane of collecting duct principal cells at postnatal day 1, 7, 14, 21, and 32. Surface area density and average optical density of AQP1 positive cells in proximal convoluted tubule and thin segment of medullary loop and AQP2 positive cells in collecting duct in kidney of filial M.meridianus increased (P<0.05 or P<0.01) at postnatal 7 day, but there was no significant difference from postnatal day 7 to postnatal day 32 (P>0.05). The results showed that the expression level of AQP1, 2 positive cells in kidney of filial M.meridianus increased at postnatal day 7, when the ability of water reabsorption of proximal convoluted tubule, thin segment of medullary loop and collecting duct increased. AQP1, 2 might play an important role in urine concentrating of filial M.meridianus kidney to regulate the balance of water in kidney.