Abstract: Objective To analyze the characteristics of peripheral blood parameters in patients with intestinal Behcet's disease (BD) and its correlation with disease activity, and provide a simple method for the overall evaluation of intestinal BD. Methods A total of 50 patients with intestinal BD in our hospital between January 2015 and January 2017 were enrolled into this study. Total 50 mucocutaneous BD patients (mucocutaneous BD group) and 40 patients with recurrent aphthous ulcer (RAU group) were selected as the control groups. The difference in peripheral blood parameters among the three groups was compared. The simple endoscopic score for Crohn's disease (SES-CD) was used to assign the 50 cases of intestinal BD into active group and stable group with 25 cases each group to evaluate the relationship between hematological parameters and ulcer activity in patients with intestinal BD. Results The RBC and HGB were significantly decreased, however, the level of FIB, ESR and CRP were significantly increased in the intestinal BD when compared with the control groups (all P<0.05). HGB and CRP were able to distinguish intestinal BD with mucocutaneous BD with the areas under the ROC curve of 0.826 and 0.871, respectively. The levels of ESR, CRP and FIB were significantly increased in active intestinal BD (all P<0.05), while the level of HGB was significantly reduced when compare with the stable group (P=0.001). The areas under the ROC curve of HGB, ESR, CRP and FIB for the detection of ulcer activity in intestinal BD were 0.758, 0.787, 0.888 and 0.792, respectively. Conclusion BD patients with low level of hemoglobin and elevated CRP in peripheral blood need to be paid more attentions to BD patients with intestinal ulcer. HGB, ESR, CRP and FIB are simple makers of intestinal ulcer activity in patients with BD.