Abstract: ［Abstract］Objective　To investigate expression of vitamin D receptor （VDR） and sodium-dicarboxylate cotransporter protein 1（NaDC1）in human renal proximal tubule epithelial cell （HK-2 cells） and their significance in hypocitraturia. Methods We cultured HK-2 cells under the cultivation condition of HK-2 cells. The apoptosis of HK-2 cells cultured was detected by Flow Cytometry ，and the expression of VDR and NaDC1 in HK-2 cells was detected by immunocytochemical SP method. Results The culture of HK-2 cells: The state of HK-2 cells was recorded by taking pictures. Flow cytometry: HK-2 cells apoptosis rate of flow tube number 1-4 were respectively 6.87%，6.80%，8.31% and 4.274%. Immunocytochemistry : The expression of NaDC1 in HK-2 cells: the cell membrane of HK-2 cells and NaDC1 positive control （human embryonic kidney 293 cells，HEK293 cells） were stained. While cell membrane of NaDC1 negative control was not stained. The expression of VDR in HK-2 cells: the nuclear membrane of HK-2 cells and VDR positive control （human lung cancer cell line A549 cells） were stained. While nuclear membrane of VDR negative control was not stained. Conclusions The apoptosis rate of the HK-2 cells cultured is relatively low，and the cells are in good condition. VDR and NaDC1 are respectively expressed in the nuclear membrane and cell membrane of HK-2 cells. Both VDR and NaDC1 are associated with the occurrence and development of hypocitraturia. We conclude that VDR may be involved in regulating the activity or expression of NaDC1.