Dunhuang documents refer to a large number of documents (with a few woodcuts) written in the stone chambers of the Thousand Buddha Cave in Dunhuang about the Tang and Five Dynasties. Most of them are written by hand in Chinese, in addition, there are a small number of ethnic minority written materials. The discovery of Dunhuang documents (discovered in A.D. 1899, before the stone chamber was sealed for a long time and unknown to the world) has become a major event in the cultural history of our country, with far-reaching influence. Mr. Yao Wang, an expert in Dunhuang literature research, once said: "It provides rich, novel and credible real documents and empirical materials for cultural classics, history, archaeology, literature, art, language, writing, nationality, religion and even the history of science, and expands and promotes the research work of these disciplines." (Introduction to Tubo Dunhuang historical documents).

Similarly, Dunhuang documents have brought a glimmer of life to the study of Tibetan culture. Among several minority volumes of Dunhuang literature, Tibetan literature (all written by hand) is the largest, with rich contents, including historical works, folk literature works, translated Han historical materials and stories, translated Indian stories and copied Buddhist classics.

(1) Folk literature in Dunhuang literature. It includes oracles, aphorisms, proverbs and stories. Oracle Bone Inscriptions in Dunhuang ancient Tibetan literature, each paragraph consists of two parts, namely, the text is a poetic Oracle Bone Inscriptions, followed by an essay explaining how this Oracle Bone Inscriptions was realized. Poetry in Oracle Bone Inscriptions belongs to literary works. Oracle Bone Inscriptions's thoughts mostly describe the beautiful natural scenery of the Qinghai-Tibet Plateau: leisurely Mu Ye, clear water by the lake, willow branches, birds, sheep, crops and so on. It makes people feel pleasing to the eye. Artistic techniques (according to the study of Tibetan literature history): The meter of poetry is basically six-syllable sentences, each ranging from four to dozens, free and lively. There is a calling word "Jie" in front of each song, and the third syllable of each sentence mostly takes "you" as the background sound, which plays a homophonic and rhyming role. Some poems can be segmented, and most of the words between paragraphs have corresponding relationships, but they are not so strict. Each paragraph is parallel, and * * * expresses a central idea. There are two Oracle Bone Inscriptions with four sentences and six syllables, which is the source of the popular "Hehe" folk song (that is, the meter of four sentences and six syllables and three meals) of later Tibetans. Oracle Bone Inscriptions also uses straightforward and figurative methods. Therefore, it vividly describes people in real objects, which is very valuable in the history of Tibetan literature.

The maxims in Dunhuang Tibetan literature are mostly to persuade people to do good and abstain from evil, to honor their parents and to preach fatalism. There are four, five, six and many sentences in the meter, all of which are seven-meter poems. Simple language and straightforward reasoning are one of the sources of later writers' aphorisms.

There is a songba proverb in Dunhuang Tibetan writing volume, with thirty or forty * * *. The content includes dealing with people, managing families and describing social phenomena. For example, the proverb about running a family: "A son is smarter than his father, and his family is as prosperous as a fire burning on the grassland;" The son is more stupid than his father, and his family is ruined and washed away by the water. " Sparrows like the dawn and owls look forward to the night. "This proverb reveals some objective truth, which has been passed down to this day and is cherished by people. This proverb in Dunhuang documents is mostly two proverbs, which adopts symmetry and metaphor in rhetoric. Tibetans are humorous and good at expressing their thoughts and feelings with proverbs and aphorisms.

There are also legends in Dunhuang Tibetan literature, such as the legend of Nie Chizanpu, the legend of the first generation of Zanpu (King) and the legend of Zhigong Zanpu. At the same time, there are stories such as "Kimboneki brothers and Zeng Geba Xin sisters", "Bai Gabai Xi and Kimboneki". These two stories have vivid plots, which break away from the framework of myth and become stories based on social life.

(2) Historical works in Dunhuang Tibetan literature. Among the Tibetan historical documents in Dunhuang, there are biographies of Zanpu and Chen Wang, such as Zhi Gong Zanpu Biography, Song Zan Gambu Biography, Song Zan Gambu and his ministers' Celebration Songs, On the Qin Tombs and Tang Generals, etc. In addition, there are some inscriptions, epitaphs and temple inscriptions. , all belong to the category of Tubo historical biography literature.

Biography of Zampa and Singing of Chen Wang mainly reflect the history of the establishment, formation and development of the Tubo Dynasty. This paper describes the process of many scattered and independent tribes and countries on the Qinghai-Tibet Plateau from the 6th century to the 9th century. After long-term exchanges and wars, they gradually moved towards reunification and established a powerful Tibetan slavery regime, as well as the deeds of outstanding figures. These documents not only become precious historical materials, but also are the oldest outstanding Tibetan literary works. Biography artistically reproduces history and praises heroes with literary brushstrokes. In these biographies, some important and influential events are described. For example, two generations of Yalong tribal leaders Dabney Sai and Nari Renzan annexed Supi; Songzan Gambu Pindabu, Kampot, Nyangbu and Supi Rebellion. Conquer Tuyuhun; Chidusong conquered Turks and Nanzhao; Chisong Dêzain conquered Khotan, invaded Chang 'an, put down Nanzhao rebellion, and so on. At the same time, it also recorded in detail the sharp contradictions and fierce conflicts within the ruling class. For example, The Biography of Songzan Gambu records the contradiction and struggle between Songzan Gambu and Shangnang, and between Songzan Gambu and Qiongbu. The biography of Chidusong records the conflict between Chidusong and the Gaelic family (the Gaelic family coveted Zampa's throne, and Chidusong later removed him by force). In addition, the biography also records the friendly relations between Tubo and neighboring countries, such as marriage and envoys. In art, biographies focus on major historical events and characters, and are good at depicting characters and paying attention to language; It is also successful in plot composition, poetic dialogue and rhythmic literary form expression, which embodies the highest level of historical biography literature at that time.

In Dunhuang Tubo literature, there are also some prose inscriptions worthy of attention, mainly a number of vows and bells, which are basically descriptive words such as vows and prayers. Including Sino-Tibetan friendship (such as the famous Tang Fan tablet), praising Pu's achievements, recording the achievements of ministers, swearing to believe in Buddhism and worship the law, granting royal privileges and so on. The inscriptions are all prose, with concise words, fluent language and clear narrative.

In a word, Dunhuang Tibetan is the oldest Tibetan people have ever seen. It is of great value to the study of Tibet's social history, religious beliefs, literature and art, language, customs and habits, and ethnic exchanges. It makes people have a deeper understanding of the politics, economy, culture and society of the Qinghai-Tibet Plateau in the Middle Ages, and attracts more and more attention from scholars at home and abroad.