Hsün-tzu(荀子, BC298?～238?) was one of the prominent philosophers in the history of Confucianism. This article is to understand Hsünt-zu`s human understanding and self-culture. The major understandings of this article are followings. 1. In the discussion of human nature, Hsün-tzu argued that the original nature of human is evil as an innate natural gift. And he assumed the human nature in the state of nature lies in selfish desire, which could turn to evil unless adequately supervised. Thus he suggested that man should make efforts realize the goodness through sage-made ‘Li’(禮). 2. Hsün-tzu tried to understand the moral possibility of human being through ‘Chêng’(誠). He did treat the good as not the transcendental thing but the immanent one in human mind. And he asserted that the revealing of the good is concomitant with being constant the mind. If man makes a constant effort to improve himself in an everyday experience he can be the sacred. 3. Hsün-tzu asserted that the nature of the sacred is identical with that of the common. But he also argued that the real difference between the sacred and the common is originated from the efforts getting Wei(僞). Hsün-tzu stated that the sacred is a man who reached a state of supreme goodness, after he had repeatedly trained through ‘Chi Wei’(積 僞), and internally deliberated and contemplated through ‘Hsü I Êrh Ching’(虛 壹 而 靜).