Zhang Huiyan is one of the founders of both the Yang Hu School and the Changzhou Ci School. Different from the Tongcheng School with its singular interest in advocating Han Yu and Ouyang Xiu, Zhang models his prose writing on various sources, and his uniqueness is closely related to his theory of fu. Zhang Huiyan's theories regarding the prose genres are connected with his theory of ci, while they are even more connected with his theory of fu. In particular, Zhang captures the essence of fu writing of earlier times and integrates them, along with his own writing experience of fu, into his composition of prose, deeply affecting the structuring of his studies of the prose genres and his own prose writing. To explore Zhang's theories regarding the prose genres, we cannot but discuss his study and writing of fu. This study attempts to examine Zhang Huiyan's theory of fu so as to further explore the connection of it to his studies of the prose genres, while commenting on its function and value in relation to the structuring of his studies of the prose genres.