Several recent studies show that midazolam has the immunoregulation effect and trend of suppress the inflammatory response, but the result is controversy, the possibly reason is the different immune status. Now there is the guideline about the different immune status: the normal immune function means that the value of mHLA-DR is more than 15000 monoclonal antibody; moderate-sever immune suppression means that the value of mHLA-DR is in the range of 5000 and 15000 monoclonal antibody; the immune paralysis means that the value of mHLA-DR is less than 5000 monoclonal antibody.