Abstract: Although Puritanism is not Hawthorne’s religious belief,it bears a longstanding and deep influence on his literature because Puritanism is Hawthorne’s theoretical weapon to understand human beings and society. The Scarlet Letter is just a warning book which Hawthorne contributes to his contemporaries. In this novel,Hawthorne views the inchoate American dream and the early-stage ooming of economy in America through the perspective of Puritanism,and comes up with a warning that the rebirth of human being does not follow the social development. Hawthorne believes that human beings are naturally evil and all people have a scarlet letter at their bosom,but his contemporaries have forgotten their scarlet letter and are facing a danger of another fall,so he points out that the only possibility of salvation lies in the brave deeds to re-put on the scarlet letter,to acknowledge the sin，to face the evil and to take up the obligations.

Key words: Puritanism, the scarlet letter, sin, obligation, salvation