Writing historical encyclopedias which were initiated by Ibn Khallekan after writing Wafayat Al-‘Ayan in the seventh century was followed and completed by writing two encyclopedias of Alwafi Bilwafayat and ‘Ayan Al’asr. The dates of deaths in translations were considered by the writer and in most of the translations he has recorded dates of deaths in alphabetical edition as being a common feature of the encyclopedias. In many translations, he has expressed his own idea about the translators and even in some cases has kept a recording of the translators’ appearance and ethical characteristics. Although the mentioned encyclopedias include some deficiencies, but they are very important because of including lots of translations from Muslim scholars especially in the eighth century during development of cultural studies and Islamic civilization. The paper attempts to provide an answer for the question: what may be counted as Safadi’s motivation in writing these works? Also, some topics such as historiography method, resources, literary style, organization style, importance and pathology of these two encyclopedias will be analyzed and criticized.