Jennie Gerhardt is a great naturalistic work of Theodore Dreiser.The heroine Jennie has long been regarded as the representative of the laboring people.Brand and Lester are selfish bourgeois who dally with Jennie and then desert her.Some reviewers contend that Dreiser eulogizes the virtues of honesty,generosity and unselfishness of the laboring people and criticizes the hypocrisy and ugliness of the bourgeoisie.This thesis intends to use text analysis to study the three main characters and their tragedies so as to prove that Dreiser holds deep sympathy towards the characters and shows the helplessness of the human beings under the forces of fate and environment.The tragic color in this novel reveals the author's pessimistic life attitudes.