Tarikh-e Nishabur (history of Nishapur), authored by Hā kem-e Nishā buri (d. 405 H. /1014), is one of the oldest and most creditable local histories ever written in the Islamic World. This work, rightly called “ Khorasan History “ because of its immensity and importance, appears to have been hugely intensive but now no longer extant. In addition to political, geographical, and cultural aspects of Greater Khorasan, the Tā rikh-e Nishā bur contains letters and documents that are of great help in shedding light on the scientific state in various parts of Khorasan. The book addresses a wide range of different subjects in the form of detailed life stories, this all being indicative of the author's use of an enormous number of sources on various scholarly fields. This article presents research made to identify the written and oral sources of the Tā rikh-e Nishā bur, including hadith books, local histories, kotob-e rejā l (biographies of prominent scholars), accounts and stories, books of poetry, Sufi texts etc. The research is based on quotations made from other sources, especially from the sole remaining abridged version of the Nishā bur History produced by Khalifeh-ye Nishā buri.