This essay redesigns the model of moral development from viewpoint of Nasir al-Din al-Tusi. Emphasizing on the possibility of moral evolution and finding the meaning of development in the works of Nasir al-Din al-Tusi, this paper compares his conception of moral development with Psychologists of growth from generalization of the definition of perfecting. The thinkers of moral development emphasize on the definition in terms of moral factors. Having explained the process of moral development, we define the nature of moral development from the aspects of the quality of composition and the priority of factors. The conceptual analysis, propositional analysis and systematic analysis from the works of Tusi have been the means and methods of this survey. Tusi, like Greek philosophers, has paid attention to the role of cognition in the moral evolution. The deduction and inference of general and particular moral subjects, the source of behavior, from the epistemological presumptions of the intellect is done from the way of practical reason. The role of factors like emotions, gender, bodily factors, exterior-environmental factors has been studied in this paper. Accordingly, the moral function of humans, active process with natural origin, entails the ordering of human behaviors by cognition in the context of environmental norms and values, in a way that during time and by exercising and experiencing, this order for humans will become an inner disposition, that is the underlying self-constructive values. This moral evolution, in a mannered form like a step by step model, begins its forming from the childhood and continues to the maturity, and on maturity has various levels and ranks. For each of these levels, Tusi has mentioned some educational principles.