Carrie is always dreaming while the rocking chair is rocking again and again, this is the deep impression on us after we read "Sister Carrie" which is the first novel of Theodore Dreiser. In this novel the protagonist Sister Carrie is a controversial person. This paper tries to analyze the character of Sister Carrie in order to find out why what she has finally achieved is just extreme void and unhappiness, and shed light on how the author calls warmly for human intuitive knowledge, attacks vigorously the society of money omnipotent, and further more exposes bourgeois society's darkness.