Abstract: Objective To observe the pathogenic role of 25-hydroxy vitamin D3 and vitamin D antibodies (VD-Ab) in patients with systemic lupus erythematosus(SLE). Methods The complete data of 90 SLE patients from November 2013 to March 2015 were set as the case group and divided into untreated group and treated group according to whether the patients accepted Vit D and relevant treatment, meanwhile 60 healthy volunteers having medical examination in the hospital during the same period of time were enrolled as control group. The serum 25-(OH) D3 and VD-Ab levels were observed and compared between the untreated and treated groups, the case group and control group. Results The serum 25-(OH) D3 level of the case group was significantly lower than taht of the control group. There was no statistically significant difference between serum 25-(OH) D3 levels of the untreated group and treated group (P > 0.05). As the active degree was aggravating, 25-(OH) D3 level gradually reduced, VD-Ab had no statistical differences between the untreated and treated groups, the untreated group and the control group, and the treated group and the control group (P >0.05). Conclusions Decrease of 25-(OH) D3 level in SLE patients is not associated with Vit D treatment. However as the active degree is aggravating, 25-(OH) D3 level gradually reduces. There is no relationship between VD-Ab and Vit D level.