At present, the detection data of many duplicate checking systems depend on the detection range of the duplicate checking system itself. The detection scope of VIP includes: full-text database of China sci-tech journals, full-text database of doctoral and master's dissertations, full-text database of foreign characteristic documents, full-text database of major newspapers in China, characteristic database of major conference papers in China, joint comparison database of university papers, patent characteristic database in China, full-text database of VIP priority publications, Internet data resources, Internet literature resources, Hong Kong, Macao and Taiwan literature resources and book resources.