ObjectiveTo explore the serum homocysteine (Hcy) level and its influence factors in systemic lupus erythematosus (SLE) patients.Methods90 SLE patients were included in the study. According to the systemic lupus erythematosus disease activity index (SLEDAI) score, 41 patients were in active stage (> 9 scores), 49 patients were in inactive stage (≤9 scores), while 46 healthy individuals were selected as controls. Total cholesterol (TC), triacylglyceride (TG), serum creatinine (Ser), C-reactive protein (CRP), serum cystatin (cystin c, CysC) and Hcy level were measured. Analysis on the relationship between Hcy level and SLEDAI score, as well as serum indicators was conducted.ResultsThe levels of Hcy, TG, TC, CRP and CysC in SLE patients were higher than healthy controls (P< 0.05), and the serum level in active sle patients was higher than inactive sle patients (P< 0.05). there was no significant difference in ser level among the active sle patients, inactive sle patients and healthy controls (P>0.05). There was a positive correlation between Hcy level and SLEDAI score (r=0.698 3,P< 0.01), as well as cysc (r=0.597 5,P< 0.01). there was no significant correlation between hcy level and crp, tc, tg and ser levels (P>0.05).ConclusionThe Hcy level in SLE patients was higher than healthy controls. The level of Hcy was positively correlated with the degree of disease activity. The Hcy level and SLEDAI score can be used as indicators to evaluate the activity of SLE.