Objective To investigate the expression of serum vitamin D receptor (VDR) in rheumatoid arthritis (RA) with different characteristics, and analyze its association with disease activity. Methods 120 RA patients from September 2021 to September 2022 in department of Rheumatology and Immunology, Peking University International Hospital and 30 health controls were enrolled. The expression of VDR were detected by Enzyme-linked immunosorbent assay (ELISA), and the correlation between the expression of VDR and clinical characteristics and laboratory tests in RA patients was explored. Results The serum levels of VDR in RA patients was significantly higher than that in the control group; The levels of VDR in seropositive RA patients was significantly higher than that in the control group. The levels of VDR in RF-positive and anti-CCP positive RA patients was significantly higher than that in the control group, no difference between RF-negative and anti-CCP antibody positive group, or RF-negative and anti-CCP antibody negative group and control group. The levels of VDR in both increased ESR and CRP group, increased ESR and normal CRP group, normal ESR and increased CRP group and both normal ESR and CRP group RA patients were significantly higher than that in control group; The levels of VDR in high and moderate activity were significantly higher than that in control group. However, no difference was found in low disease activity, stable disease activity compared with control group. There were no differences between male and female RA patients, between eRA and RA patients, between seronegative and seropositive RA patients in serum level of VDR; The levels of VDR in RA overlap with systemic lupus erythematosus (SLE) were higher than those without SLE. In addition, the serum VDR levels in RA patients with and without complications including Sjogren's syndrome (SS), Osteoarthritis (OA), interstitial pneumonia disease (ILD), thyroid gland diseases (TGD), Osteoporosis(OP), hypertension and Diabetes mellitus (DM) showed no differences. The level of serum VDR were significantly positively correlated with erythrocyte sedimentation rate(ESR), C-reactive protein(CRP), rheumatoid factor(RF), immunoglobulin A (IgA), immunoglobulin M (IgM), immunoglobulin G (IgG), and DAS28-CRP, and negatively correlated with Complement 4 (C4) in RA patients. Conclusion Serum VDR is elevated in RA patients and correlated with disease activity