The origin and ingredients of Kaihua paper used for imperial printed books of the Qing Dynasty have long been controversial issues in the academic world. In recent years, some scholars have compared archives and existing ancient books, finding that the Qing Dynasty “Kaihua paper” is actually “Liansi paper” and that “Kaihuabang paper” actually “Jingxianbang paper”. Both papers come from Jingxian County of Anhui Province. In our study, we analyzed the fiber micrographs of the residual fragments from four kinds of Kaihua paper and one kind of Kaihuabang paper, and compared the microscopic features of the ancient samples with those of a control sample from the perspectives of fiber morphology, fiber width, fiber grain, gum coating and crystal morphology. The results suggest that the fibers of the five residual fragments are all derived from wingceltis bark only, which is consistent with the results of research on historical materials. According to the mutually-verified conclusions, the so-called Kaihua paper and Kaihuabang paper used for imperial printed books of the Qing Dynasty could well be wingceltis paper from Jingxian County, Anhui Province.