With its spiritual dimension and by focusing on the attitude and behaviour of sufis, sufi psychology will benefit modern psychology. In the past, dealing with mental health and with the evolution of the human personality was left to spiritual and religious disciplines, but today these issues are reserved to psychologists and psychiatrists. Some of them have started to seek inspiration within spiritual and religious realms in an effort to apply that knowledge to their practice. They show specific interest towards sufi literature and bring sufi practices and knowledge into their own therapeutic practices. In this article, we have examined the fundamental bases of the evolution of the sufi personality according to Sadr al-Din Qunawi, a 13th century sufi from the Ibn 'Arabi tradition. We have tried to study the metaphysical and psychological bases of the structure of the sufi personality and their effects on human attitudes and behavior.