Jiaolong capsule (JLC) was approved for the therapy of gastrointestinal diseases by the State Food and Drug Administration (SFDA) of China. It has a satisfactory curative effect in the treatment of patients with inflammatory bowel disease, however, the mechanism remains to be elucidated. In current study, the effects and possible mechanisms of JLC on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis were investigated. Sulfasalazine and JLC were administrated orally and initialized 6 h after TNBS enema, once a day for seven consecutive days. The effect of JLC on intestinal microbial populations and LPS/TLR-4/NF-κB pathway was observed and assessed. Thirty female SD rats were distributed into six groups randomly and equally, namely, control, TNBS, TNBS + sulfasalazine (625 mg/kg), and TNBS + three different doses of JLC (25, 50, and 100 mg/kg) groups. The effect of JLC on restoring normal structures of colorectum and repairing colonic damage were superior to that of sulfasalazine. JLC showed a positive effect in re-balancing intestinal bacteria population of colitis, and suppressed the activation of LPS/TLR-4/NF-κB pathway. The results suggest that JLC demonstrated a beneficial effect on treating colitis in a rat model. The possible mechanisms may be through the regulatory effect of intestinal commensal bacteria and down-regulation of LPS/TLR-4/NF-κB pathway. Copyright © 2020. Published by Elsevier B.V.