Sutra of Golden Light, one of the most important state-protecion canons in Central Asia and East Asia, is also a demanding sutra in ancient Japan. The sutra emerged in Japanese history during Emperor Tenmu’s reign, while it should have been introduced to Japan a century earlier. Through the historical records, the cult of Sutra of Golden Light in ancient Japan can be indicated. Simultaneously, in the later half of the seventh century, Japan was being structured. That is to say, the ruler emphasized Sutra of Golden Light when the state of Japan was being bulit. To investigate the connection between Sutra of Golden Light and the building of Japan as a state, the follwing thesis will be divided into three parts: initially, through analysing different versions of Sutra of Golden Light and various commentaries, the first part will suggest the possible idea related to the sutra that were likely to be spread in ancient Japan. Then, by exammining the historical materials, the second part will illustrate the religious and political environment during Emperor Tenmu’s reign, and discuss how Sutra of Golden Light being interpreted under the circumstances. Finally, the last part will focus on the disaters in ancient Japan. Since earthquake is the most significant disater in Japan, and there were many earthquakes during the time according to the historical accounts, inspecting the relations between the sutra and earthquakes can reveal how people perceive the sutra as state protection during and after the disater. In summary, the thesis will focus on the interpretation of Sutra of Golden Light and the construction of the state of ancient Japan.