Abstract: Walden, a masterpiece of American writer Henry David Thoreau, is honored as one of the Western classics, enjoying a prominent position in the history of American literature and world literature. The process of canonization of this book is directly related with American historical and cultural context from late 19th to early 20th century. Based on the concept of constructivism, it can be found that there are three major forces promoting Walden to become one of the classics, i.e., the business marketing strategy of Houghton Mifflin, the great compliment of the critics and the debate of the literary historians, and the changes of social mores.

Key words: Thoreau; Walden; marketing strategy; natural literature