This study examines the life and works of Abu Talib al-Makki, one of the greatest Sufi writers of the fourth Islamic century, with special attention being paid to his mystical doctrine, as expounded in his chief work entitled “Qut al-Qulub fi mu‘amalat al-mahbub”. In analysing al-Makki’s mystical doctrine, detailed studies are made in this thesis in relation to al-Makki’s concept of religious life as a preliminary basis for the higher mystical life, and his concept of mystical life with special reference to his concept of the heart, science of the heart, theory of knowledge, gnosis, and finally his concept of the mystical states and stations. (Islamic Philosophy/Sufism)