In 1950s, a documentary movement stood up greatly in Postwar Japanese literature. I researched the reason why the postwar literature which was performed in various forms rushed the documentary movement, and inspected mainly on the origin and the issue of the documentary movement through chapter 1 and 2. The debate on documentary literature was relatied with the debate on national literature which intended to create "the nation" through "Hanbei" or the anti-Americanism. I made clear that the documentary movement was deeply concerned with the actuality in that times. In Chapter 3, I reserched the two different flow of the documentary movement focused on Abe Kobo. I made sure it on the focus of the period of "Genzai no Kai" that considered the "reportage" as the Record. In Chapter 4, I reviewed the meaning of that time why the word of "reportage" changed with "documentary" at the next "Kiroku Geijutsu no Kai" period. I considered the connection between documentary and the mass. Conclusively, postwar documentary movement was not only the issue of expression but also the engagement of politics of the 1950s. Finally, I want to clarified that there were two sides of continuation and break for documentary movement in 1950s.