Education and training are closely related to the growth and perfection of human kind and to his worthy life. As man is an entity with rational attitudes, his education should be based on thought and reason. Based on this rationale, and through descriptive- analytical study of educational methods of Prophet Khidr (peace be upon him), this article aims to answer the following question:” How can Prophet Khidr’s educational approach be explained according to basis of the rational system of education”? This paper findings show that Khidr's teaching method emphasizes the subtle points which can be used in a scientific system of education. For example; Prophet Khidr first does a kind of need analysis based on his travelling companion’s personality, then he poses the problem and through asking questions and giving numerous real examples and based on the simplification principle, he evaluates his companion’ s point of view and justifies his own logic and wisdom. He then leaves his companion while all his questions has been answered and he has been taught to expand this logic and wisdom in the other similar situations of life.