As for when it was written, at the very end of the manuscripts there is a note that it was "written in the sixth month of 940," so the theory that it was written immediately after Masakado's death predominated beginning in the Meiji period, but since entering the Showa period, the viewpoint has emerged that argues this date was actually a fabrication that is supposed to be attached to Masakado's message from the underworld.
成立年代も、巻末に「天慶3年6月記文｣とあることで、将門死去の直後に書かれたとする説が明治時代以来支配的であったが、昭和に入り、この記年は冥界消息に付随する虚構であるとの指摘がなされた。