In 1868, the Meiji government decided to establish a military system that would improve not only the fighting capacity but also the military discipline of Japan's army. On the one hand the Meiji leaders rebuilt Japan's army with inspiration from Western models, initially the French. On the other hand they adopted from Western countries modern military justice system, that helped to shape gradually the Japanese navy and army in the 19th century.;This thesis delves deep into the introduction and evolution of the military justice system in the Meiji era, in an effort to explain how it helped reshape military discipline within the Imperial Japanese Army. Utilizing a range of primary sources, it studies the creation and enforcement of the military justice system from a military history rather than legal history perspective. It is hoped that this thesis reveals the crucial role that the military justice system played in Japan's military modernization during this period. The findings also explain why military discipline of the Imperial Japanese Army began to decline again after the Russo-Japanese War.