The life and works of Erinshōki, the third patriarch of the Japanese Obaku Zen tradition, have not been fully studied by scholars. As a member of the research project undertaken by the Center for Buddhist Studies of Fo Guang University, I was able to survey rare classical documents held in the National Diet Library in Tokyo, Komazawa University, Obakusan Manpukuji Bunkaden in Kyoto and the Nagasaki Museum of History and Culture. I discovered three of Erinshōki's recorded sayings works, two poetry anthologies and various other relevant works such as memoirs or historical works. By analyzing the published anthologies of Chinese Buddhists resident in Japan and comparing them with relevant writings of other Buddhists in the Obaku Zen tradition, I have been able to create a more detailed biography of Erinshōki's life, and further provide corrections to chronological biographies included in previously published anthologies of his collected works.