Abstract: Japanese Siddham books with broad range, which origin from ancient Indian and develop in ancient China during Han, Tang and Song dynasties, accumulated step by step to become system of knowledge after introduced into Japan. The art of Siddham consists of not only its letters itself, Chinese characters, kana, pronounce of letters and meaning of letters so on.; but also is involved to the many aspects of religion, music and literature etc. But it is pity these books were paid less importance by the scholars, ...
