Active Intellect, a being higher than natural world, devoid of matter and it’s rules, self - subsistent, without position and pure actuality. This intellect is a connecting link between incorporeal beings and material things and the source of emanution of multiplicities in the natural world and has gained a prominent role alongside all actions pertaining to the management of the world of matter. In Ibn Sina’s view the immediate and mediate role of active intellect in all the stages of human life is apparent. In the domain of creating man active intellect by undertaking a mediate role in producing temperament and an immediate role in effusion of soul to the disposed temperament shows itself. Also active intellect has a very difinitive role in the perfection of soul especially the rational faculty and actualization of theoritical and practical reason. Active intellect is considered as regulating the relation of rational soul with the invisible world in dream and in waking and in the problem of prophethood as well it appears as the angel of revelation. The mode of the survival of soul after death depends on the quality of the relation of soul with the active intellect and the souls which due to the intensity of conjunction have achieved to practical and scientific perfection, after death and leaving the body achieve the stage of complete union and survive according to the rule of active intellect, but incomplete souls which lack actual intelligible have no relation to active intellect but by belonging to celestial souls achieve to some stages of perfection.