Sepsis is life threatening organ dysfunction caused by microcirculatory dysfunction. With progression of sepsis, the patients are likely to develop septic shock which is associated with multi organ dysfunction. To treat sepsis and septic shock, Thrombomodulin alfa (TM alfa) was developed. Direct observation of the microcirculation may provide new and rich information in terms of the effect of TM alfa on sepsis. Thus we conducted rodent experiments in which we observed the microcirculation with a non-contact optical imaging setup and measured lactate value from collected blood. From the acquired motion pictures, we estimated the blood velocity. As a result, from experiments, the sham rats showed no significant change in both lactate value and the blood velocity during the observation. On the other hand, lactate value of the septic model rats increased and the blood velocity of them decreased. Lactate value of the septic model rats treated with TM alfa decreased after showing an increase while the blood velocity of them increased after showing a decrease. These findings suggest that microcirculatory alteration may be a sign of sepsis as well as septic shock progression and that the TM alfa may be effective for the treatment of sepsis and septic shock.