Abstract: Most of American poet Robert Frost’s poems superficially depict natural scenery, but they contain profound philosophy indeed. Three of his most famous works, Stopping by the Woods on a Snowy Evening, The Road Not Taken and Mending Wall, all use metaphors to present a dilemma of choice regarding the state of human existence. Stopping by the Woods on a Snowy Evening reflects the conflict between ideal and reality; The Road Not Taken shows the important decisions faced at the crossroads of life; and Mending Wall depicts a dilemma in human relations field. The state of existence mapped out in the three poems inspires people to think about life, so that they can get out of difficulties and make wise choices.