Abstract: Zhao Cigong is the most diligent scholar in Du Fu's poem study in Song Dynasty.His studies covered a large scale and his annotation is the first-rate.His explanation, which was based on comprehensive collection and thorough analysis of written literature and oral materials in Du Fu's poems, was appropriate, refined and grounded, especially in correcting the false in previous studies.In short, Zhao Cigong's Du Shi Xian Hou Jie is the masterpiece in the early study of Du Fu, and he is thus one of the most successful scholars in annotation study of Du Fu.