Objective · To analyze the related factors of disease activity of Behcet disease (BD) patients. Methods · The clinical records of 178 patients with BD who were admitted to the Department of Rheumatology and Immunology, Renji Hospital South Campus, Shanghai Jiao Tong University School of Medicine from January 2013 to December 2018 were collected, and the clinical manifestations and laboratory indexes of the patients were analyzed. Electronic medical record-based activity index (EMRAI) was used to evaluate the disease activity, of which the related factors were explored by univariate analysis and Logistic regression analysis. Results · The ratio of males to females in 178 BD patients was 1.67:1. The results of single factor analysis showed that there were statistically significant differences in EMRAI scores among the patients with different genders, education levels and courses of disease, as well as between the patients with or without abnormal C-reactive protein, paroxysmal abdominal pain and temperature rise (P<0.05). Multivariate Logistic regression analysis showed that the related factors of EMRAI score were course of disease, C-reactive protein and treatment plan (P<0.05). Conclusion · The disease activity of BD patients is correlated with the course of disease, C-reactive protein and treatment plan.