AbstractThe Old Man and the Sea tells the frustrated experience that the old fisherman fishes in the course. The theme is deep, and it is a song of praise of heroism. “But man is not made for defeat. A man can be destroyed but not defeated” has been the classic saying and the old man also has been the most typical and the most representative of the Hemingway’s “tough guy”. When Hemingway talked about the successful factors later, the little boy was mentioned in the same breath with the old man.This paper starts with the details and it is divided into two main parts to discuss the indispensable roles of the little boy in the novel. It is him who helps to perform the theme of “grace under pressure”: during 40 days, the old man with the little boy went to fish but without taking a fish, when his situation was getting worse step by step, the little boy’s leaving was the heavy pressure that achieved the extreme stern for certain. However, it was so “heavy pressure” that his manner was graceful when the old man faced afterwards defeat and his optimistic, generous life attitude was worthy tasting by people carefully; it is him who plays the role of leading, inspiring to the readers, and increasing the appeal of the work, enriching the content of the work: although the little boy appears only at the beginning and the ending in the novel, there is nothing in his inner state but the old man, so his attitude and emotions towards the old man affects the readers’ emotions for the old man quietly and gradually. And it is unavoidable that his inner feeling leads and impacts the readers’ emotions.Key words: roles; the little boy; the old man; grace under pressure; The Old Man and the Sea