Abstract : Rheumatoid arthritis (RA) is a chronic inflammation, multisystemic autoimmune disease that accounts for nearly 18 percent of all deaths. Etiology is remain unknown, but interaction between genetic factor and environment can activate the immune response. DAS 28 is a scoring system to assess the disease activity of RA. Vitamin D is produce from UV exposure and dietary intake. Vitamin D can suppres the immune system by maintain the balance between TH-1 and TH-2 and also can reduce the inflammation by inhibit cytokine proinflammation. This research is a cross-sectional study, conducted from July 2022 to December 2022 at the Makassar rheumatology clinic, Dr. Wahidin Sudirohusodo and its network. The subject is patients with rheumatoid arthritis according to ACR/EULAR 2010 who meet inclusion criteria. The degree of disease activity was assessed by DAS 28, then divided into 3 groups (mild, moderate, and severe). 25-hydroxyvitamin D3 was measure by the ELISA (enzyme-linked immunosorbent assay) with results in ng/mL units of measure. Data analysis used SPSS version 22 and spearman correlation test. In this study, a value (rs: -0.998) was obtained, there was a strong relationship between vitamin D levels and degree of RA disease activity, which is the lower the vitamin D levels, followed by an increase in RA disease activity. An inverse relationship was found between vitamin D levels and the degree of disease activity in rheumatoid arthritis.