The Adventures of Huckleberry Finn is honored as the most typical novel of American literature after the Civil War. This story unveils the hypocrisy of religion and scoffs at the conventional social principle. Affected by the deep-rooted racial discrimination, Huck pays little respect to the black slaves as other white people do at first. After embarking on the raft with Jim together, he has got the chance to know more about what the black slave truly is. He never stops struggling inside, and eventually Jim's kindness and loyalty helps Huck to waken humanity in his heart and defeat his moral conflict. Therefore through the deepened analysis of the plot and the author, the reasons for the change of Huck's morality can boil down to social conventions, Huck's complicated character, and moreover the democratic ideal of Twain.