Abstract: The Thoreau's masterpiece Walden can be considered as the classic one in American literary history. It has rich ecological connotations. Its author loved nature and revered life. He criticized industrialized civilization and the western world view which opposes human against nature. He doubted development view which takes science and technology as the most important. He advocated the simple life and proposed the natural ecological thoughts that man should respect, protect, and return to nature and exists with it harmoniously.