Toll-like receptor (TLRs) is a type of pattern-recognition receptor that recognizes pathogen-associated molecular patterns, the important mediator of innate immunity. The aim of this study was to examine the anti-inflammatory effect of TLR2 monoclonal antibody (TLR2 mAb) on concanavalin A (ConA) induced-hepatitis. Our in vitro findings indicated that the TLR2 monoclonal antibody developed by us was able to neutralize the activation of peripherial blood mononucleated cells (PBMC) induced by ConA. Furthermore, pretreatment of mice with TLR2 antibody exerted liver protection against ConA. Compared with the isotype IgG group, the TLR2-antibody-treated group demonstrated less mortality with concomitant decreased serum level of Ast and Alt. The detailed mechanisms underlying the protection effect induced by TLR2 antibody was due to inhibition of infiltration of lymphocytes in liver induced by ConA as well as the expression of pro-inflammatory factors, such as TNF-α, IFN-γ, IL-6. Taken together, our findings demonstrated that TLR2 mAb pretreatment protected liver against ConA-induced hepatitis in mice, suggesting that TLR2 mAb is a potential candidate for therapy of acute hepatitis.