Peking University Library has a collection of 1.6 million ancient books, including over 20,000 types (over 200,000 copies) of rare books. 427 of the collected rare books are included the "National Precious Ancient Books List" and 88 are included in the "Restored Rare Books of China" series. There are also 288 pieces of Dunhuang scroll manuscripts, over 40,000 types (over 80,000 pieces) of rubbings, and over 2000 pieces of ancient maps. Both in the total number of collections and the quantity of treasures, PKU Library ranks first among Chinese university libraries and third among Chinese libraries. In 2008, Peking University Library was listed as one of the first batch of "National Priority Conservation Institution for Ancient Books".

Peking University boasts a gathering of masters and a multitude of renowned scholars. They have not only made significant academic achievements but have also left behind valuable personal documents and archival materials with high cultural and artistic value. The selected types of documents here mainly include manuscripts, letters, diaries, book inscriptions, exlibrises, photographs, certificates, and more. Here, you can find Hu Shih's manuscript of 'On Confucianism,' Deng Guangming's graduate thesis, Xu Zhimo's inscriptions in gifted books, Hou Renzhi's book inscriptions, Jiang Zehan's academic committee membership certificate of the Chinese Academy of Sciences, Hu Shih's honorary doctoral certificates, Shen Congwen's letter, Chen Hansheng's diary, and so on. These pieces outline the academic atmosphere and scholarly traditions of Peking University.

Many scholars at Peking University have a strong interest in and excel at calligraphy. Peking University Library, with submissions on anniversary celebrations and through various collecting, currently holds over a hundred pieces of calligraphy by PKU scholars. These scholars include Liang Shuming, Deng Yizhe, Zhou Peiyuan, Zhang Dainian, Fei Xiaotong, Ji Xianlin, Deng Guangming, Ren Jiyu, Jin Kaicheng, Su Bai, Luo Rongqu, Li Yining, Jin Kemu, Chen Yixin, Zhao Baoxu, Tian Yuqing, Sun Yushi, Wu Xiaoru, Li Zhimin, Gao Ming, Yang Xin, Yuan Xingpei, and others. Their calligraphy works are either bold and vigorous or elegant and graceful, with personal insights into life or copies of famous poems and verses as the content. These works not only provide aesthetic enjoyment but also inspire thought, every stroke representing the artist's character and calling for the viewer's contemplation.

Since its time as the Library of Imperial University of Peking, Peking University Library has placed great importance on the introduction of Western books. Over the years, through extensive accumulation and with its incorporation of collections from the former Yenching University, Sino-French University, and Sino-German Society, the library has amassed an impressive collection of books in foreign languages, ranking at the top among all university libraries in China. PKU Library currently holds thousands of rare books in foreign languages, the earliest publication being the Greek edition of Euclid's Elements published in Basel, Switzerland in 1533. Much of the collection features Sinology, including both major works of China Studies and translations of Chinese classics.

Since the Opium War in 1840, China's doors have been wide open. Foreign missionaries, explorers, scholars, and others came to China with cameras, and documented the minutiae of the extraordinary changes occurring during the late Qing Dynasty, described as "a period of turbulence unlike any in the past three millennia." Many of these photographs were interspersed within their written records and subsequently published, making foreign-language books an essential reference for understanding the historical, cultural, and societal transformations of that era. Through these images, we can witness the breathtaking beauty of traditional Chinese architecture that left Westerners in awe. We can also observe Western-style churches and schools introduced by Westerners and the embrace of Western influences. Vivid examples of the interplay of tradition and change, the clash and fusion of Chinese and Western civilizations, all can be found in these records.