In summary, the present study provided strong evidence of the protective effects of TREM‐1 deficiency against LPS‐induced endometritis in mice, the mechanism of which could be deduced as knocking out of the Trem‐1 inhibited the LPS‐induced production of IL‐1β, IL‐6 and TNF‐α. The gene discussed is TREM1; the disease is endometritis.