The present paper discusses Italian Renaissance philosopher Pietro Pomponazzi’s (1462-1525) conception of religion. Pomponazzi admits that belief is superior to reason, and attempts to reflect upon religion and religious phenomena within the limits of reason. He considers that supreme happiness of man is not intellectual contemplation, but perfection of virtue. Religion is the tool of improving virtues of individuals and the society, and hence ensuring man’s happiness in this life. Pomponazzi’s conception of religion is a turning point between the medieval conception of religion and the Reformists’ conception of religion, indicating the developing direction of the conception of religion since the Renaissance period: rationalization, moralization and secularization.