Abstract: Chuang Tzu??s“Tao”thought is the inheritance and development of Lao-tzu’s“Taoism”, regarding“Tao”as the essence of the world.“Tao”exists before all things and there is no beginning and ending. It is intangible but causes the generation of everything. Although“Qi”is less detailed than“Tao”in Chuang Tzu,through the discussion throughout the book, one finds that“Qi”is the material foundation of all things.“Tao”is the internal driving force that pushes and guides the flow and circulation of“Qi”, which form the image of things. Everything thereby is what it is and each has its own attribute.“Qi”, propelled, guided, and regulated by“Tao”, creates this real world full of varieties. According to this ontological view,“Tao”generates all things through“Qi”, so“ the world is nothing but‘Qi’”. Also because of this, everything exists in a different form: it can be completed or destroyed; beautiful or ugly; big or small; acceptable or unacceptable; reasonable or unreasonable. From the point of view of“Tao”, they are the same. This is the foundation of Chuang Tzu’s ontological theory that explains the unity of beauty and ugliness.

Key words: Chuang Tzu, beauty and ugliness, Tao, Qi