Together with Sabenkankyoku and Ubenkankyoku, Shonagon configured Shonagonkyoku, which was one of three Kyoku (bureaus) of Daijokan engaged in business under Giseikan (Daijin, Dainagon, Chunagon, Sangi), and had Geki, Shisho and Tsukaibe as its subordinates.
左弁官局・右弁官局とともに議政官（大臣(日本)・大納言・中納言・参議）の下で実務を担う太政官三局の一つ少納言局（しょうなごんきょく）を構成し、下僚として外記・史生・使部が属した。