Lao-tzu's thought contains many water-related philosophies. He regards water as the best guider of human beings. Through insighting the nature of water, we can understand the way of cosmos, the way of beings, and the way of politics. Base on the idea of "The best of all nature is just like water" (上善若水), this article attempts to focus on the water-image in Chinese characters implied by Lao Tzu, such as: Yuan (淵), Qing(清), Brook(谿), Hun(混), etc. These words with water image carry the ideal attitudes of life, such as modesty, tenderness, humble, tranquility , no desire, etc. This paper tries to unfold the power of will hidden in those water-image words. Tenderness (柔) as the truth, humble (下) as the good, and tranquility (靜) as the beauty-they point out the ideal personality of Lao Tzu.