Sheikhs of Ijaza in al-Kafi's Chain of Authorities

Due to prevalence of writing and its basic role in recording Shiite hadith and transmitting it to next generations and authors of the four books, this important question is raised that how one can find the sources of compiling book al-Kafi, the most important book of the four books.it can be followed by knowing Kulayni’s teachers who have given licence to him to relate hadith and their role in the chain of authorities of al-Kafi. To know his teachers first a survey of their hadiths in the chain of documents of al-Kafi should be done. Likely teachers are found. Then compare different chain of authorities in al-Kafi with other sources and demonstrate their authority to give licenses for relating hadith.