Objective: To explore the effects of Cldn14 gene knockout on renal metabolism and stone formation in rats，so as to provide reference for research in the field of urinary calium metabolism and stone formation. Methods: Cldn14 gene knockout homozygous rats and wild-type rats of the same age were randomly divided into 4 groups：wild-type control (WC) group，wild-type ethylene glycol (WE) group，gene knockout control (KC) group and gene knockout ethylene glycol (KE) group，with 10 rats in each group.The WE and KE groups were induced with ethylene glycol + ammonium chloride to form kidney stones，while the WC and KC groups received normal saline gavage.After 4 weeks of standard maintenance feeding，the urine samples were collected to detect the venous blood.The kidneys were collected for HE，Pizzolatto's staining and transmission electron microscopy.The protein in renal tissues was extracted to detect the expressions of Claudin16 and Claudin19. Results: Crystal deposition was observed in the renal tubular lumen of the WE and the KE groups，and more crystals were detected in the KE group.The WE group had a large number of intracytoplasmic black crystalline inclusions observed in renal tubular epithelial cells under transmission electron microscope，followed by the KE and KC groups.Compared with WC and WE groups，KC and KE groups had significantly decreased serum calcium and magnesium levels but significantly increased urinary calcium level.In addition，the urinary calcium level was higher in the WE group than in the WC group and higher in the KE group than in the KC group.The KE group had lower level of Claudin16，but there was no significant difference in the level of Claudin19 among the 4 groups(P>0.05). Conclusion: Knockout of Cldn14 gene alone cannot effectively reduce urinary calcium excretion or reduce the risk of stone formation in rats，which may be related to the decrease of Claudin16 level.