Al-Qadi Husayn al-Marwarrudhi is one of the important representatives of Khurasan Shaffi School. Al-Tallica is his famous work, which is one of the first commentaries of al-Muzani's Mukhtasar. One of the important features of this work is the introduction to some of the subjects of ijtihad (process of juristic legal reasoning), taqild (acting upon the word of another without asking for specific proof), ijm"consensus of jurists) and view's of the companions of the Prophet. The first systematic, complete and detailed works of usal al-fiqh (Islamic legal theory) that belonged to the Khurasan Shaffi School have reached to the present day belong to the second half of the V./XI. century, Making research on the studies which were done about usal al-fiqh and formed the basis of this period is essential to follow the development of usal al-fiqh of the Khurasan Shaffi School. Transfer of the usal al-fiqh in al-Qadi Husayn al-Marwarradhi's al-Ta'ilka make it possible to determine the literature, which was formed in Khurasan region in the period from the death of Shafi'i to the first half of the V./XI. century until the first half of the Khurasan region, which allows the determination of the usal al-fiqh. In this study, on the basis of ijma', Husayn al-Marwarradhi's method in al-Ta'lika will be examined.