The publishing of the Third Edition of Japanese Pharmacopoeia was performed after Russo-Japanese War, on July 2, 1906. In those times, the military and economical power of Japan advanced toward East Asia, and thus gradually, Japan had become one of the powerful force in the world, partly because due to the unexpected victory in the War. Thereafter, in the second decade of the twentieth century, Japan was involved in the World War I, from July, 1914 to November, 1918, which ceased the fire by the defeat of Germanic Allied Countries. In Japan, the next revise of the pharmacopoeia was performed and the Fourth Edition of it was published on December 15, 1920. The Japanese pharmaceutical industry developed remarkably in those times, during the big war and confusion in the market, by accompanying with the suitable and tentative pharmaceutical legislations by the government and the supportive aids to the civilian enterprises in the productions, supplies and distributions of the materials and medicinal products.