There have been positive and negative observations on the authorship of Prince Shotoku [聖德太子] about the Hokkegisho [法華義疏] as the first book of Japanese Buddhism. Presently, dealing with this problem, I am going to probe the background of the thought of the work. Its characteristics can be summarized into four points. 1. The essence of the work is predicated upon the Fahuayiji [法華義記] by Guangzhaisi Fayun [光寺法 雲宅]. 2. There are some parts critical to the theory of Fayun, the first part seeming to be an abstraction of the theory of a master older than Fayun. 3. The second part critical to Fayun’s theory is formed in its efforts to give a unified interpretation on the whole work in correcting some tattered part of the Fahuayiji. 4. The third part critical to Fayun’s theory is formed in its efforts to give an interpretation based upon the scripture in evading some complicated explanations of the Fahuayiji. With other evidences as well, this work is thought to be a work from Asuka period, Prince Shotoku appearing to be its author. Some parts of it are based upon Chinese writings, the first part being based upon the theory of Guangzhaisi Fayun and the second part being based upon the theory of a master older than Fayun, while the former is thought to be transmitted through Hyechong [慧聰] from Baekche, the latter through Hyeja [慧慈] from Koguryeo. Thus, the work Hokkegisho is thought to have been written by Prince Shotoku with the transmission of some theories of Chinese scholar monks through two scholar monks from ancient Korea.