This paper aims to re-evaluate Mark Twain"s later period so that we can view his later writings from much brooder perspectives. The main argument is that we should not regard Twain"s later years as those of literary failure affected by his personal disasters or growing pessimism. For this purpose, this paper analyzes one of Twain"s later writings, The Chronicle of Young Satan, written between 1897-1900 though remained unfinished. In analyzing this work, a special emphasis is laid upon the role of Satan. As a transcendent stranger with supernatural power, he plays an important role as a spokesman of Twain in his later years.<BR> The Chronicle of Young Satan reveals Twain"s most pessimistic views about human nature and human society. Throughout the whole text, Twain attacks the absurdity of moral sense and expresses strong doubts about the prospect of progress by espousing philosophical determinism. Although his frustration over modem civilization, human nature and the path of history got deeper in his later years, he never fell into the state of total despair. Even in his later years, Twain remained very much creative experimenting new literary techniques. And as a serious social critic and spokesman for his culture, he responded to the changing currents of the society in much the same way as he did throughout the earlier phases.