Objective：To determine the nuclear localization signal of vitamin D receptor(VDR)and verify its function. Methods： The nuclear localization signal of VDR was predicted by software analysis and literature investigation. A series of point mutants of VDR were constructed by a point mutation kit. The distribution of VDR in the cytoplasm and nucleus was obsened by Western blot and immunofluoresceme to determine the effect of mutation points in the entry of VDR into the nucleus. Finally，quantitatve real⁃time PCR (qPCR)was used to detect the expression of genes downstream of VDR to determine the activity of VDR nuclear localization mutants. Results：The nuclear localization signal sequence of VDR was determined to be49RRSMKRKALFLT61. The expression of a series of NLS (nuclear localization sequence)point mutants of VDR was mainly distributed in the cytoplasm. Vitamin D could neither induce these point mutants into the nucleus nor promote the expression of downstream genes of vitamin D. Conclusion：VDR nuclear localization signal can effectively control the entry of VDR into the nucleus，play the role of transcription factors，and then affect the expression of downstream genes，which provides a new platform and idea for exploring the treatment of vitamin D and VDR related diseases。