Abstract
The research is an attempt to realise the ways of transferring the textual material(died 334 A.H/994A.D) of "tabaqat muhaddithi Ahl Al-Mawsil" by Abu Zakaria al-Azdi to the later historians especially that the book are not exist at our time.The book is considered one of the lost, yet very important book about scientific and culture history of Mosul. Our Knowledge about that book came from many historical books such as "tarikh baghdad" by al-khatiib al- Baghdadi (died 1070 A.D./463 A.H.) , "Ausd al-ghaba fi ma'rifat-al-sahgaba"by Ibn al-Athir (died 1232A.D./630A.H.),"bughiat al-talab fi ta'rikh halab"by Ibn al-'Adim (1261A.D./660A.H.). Historians had been taking their information
indirectly from religions shiekhs and pupils' narratives notably Abu-Almudhafar Mansur Bin Muhamad al-Tusi who was al-Azdi's pupil.Those narratives then transferred to later historians .
