The novel tells the story of Buck was originally a dog of Judge Miller's family, after civilization, has been living in a warm valley in southern California. Then he was sold to Alaska, a cold, remote, gold-rich state in the north of the United States, and became a sled dog. The story of a dog shows that the dog in the civilized world is forced by its owner to return to the barbarism. It is written about dogs, but also reflects the world of people.