専門は大清帝国史。とくに八旗制を中心に，マンジュ（満洲）人王朝という観点から，帝国の形成・発展過程とその構造を研究している。中央ユーラシア・近世ヨーロッパ・日本の諸政権との比較国制史にも関心を持っている。
大阪大学で博士（文学）学位を取得（2000年），論文「清初八旗における最有力軍団──太祖ヌルハチから摂政王ドルゴンへ──」（『内陸アジア史研究』16号, 2001年）で第1回内陸アジア史学会賞を受賞。

SUGIYAMA Kiyohiko specializes in Qing and Manchu history. His research focuses especially on the process of formation and development, as well as the structure of, the empire from the viewpoint of the Manchu Dynasty with a focus on the Eight Banner system. He is also interested in comparative studies related to the history of regimes in central Eurasia, early modern Europe, and Japan. He gained his PhD in literature from Osaka University in 2000 and received the First Award from the Society of Inner Asian Studies for his paper “From Nurhaci to Dorgon: The Most Powerful Banner of the Eight Banners,” Nairiku Ajiashi Kenkyu (Inner Asian Studies) No.16, 2001.