Keichu was a prolific writer, whose works included "Manyo Daishoki" (Commentary on Manyoshu [Collection of Ten Thousand Leaves]), which was entrusted to Keichu by Mitsukuni TOKUGAWA, "Kogan-sho" (Commentary on Verses in Kojiki [A Record of Ancient Matters] and Nihonshoki [Chronicles of Japan]), "Kokin Yozai-sho" (Commentary on Kokin Wakashu [Collection of Ancient and Modern poems]), "Seigo Okudan" (Conjectures on Ise Monogatari [The Tales of Ise]), "Genchu Shui" (Addenda to Commentary on the Tale of Genji), "Hyakunin Isshu Kaikan-sho" (Rectified Commentary on One Hundred Poems by One Hundred Poets), and "Waji Shoran-sho" (Corrections to Errors in Japanese Characters).
著書は、徳川光圀から委嘱を受けた『万葉代匠記』をはじめ、『厚顔抄』、『古今余材抄』、『勢語臆断』、『源註拾遺』、『百人一首改観抄』、『和字正濫抄』など数多い。