This dissertation intends to study the haunting power of the past¡Xthe legacy of slavery and the trauma of racism¡Xon the lives of African Americans in Toni Morrison fiction. In this dissertation, I attempt to examine how the aftermaths of historical and individual trauma affect the formation of ethnic identity and black subjectivity, how the traumatic history is haunting across generations, how the memory of the traumatic past is mediated and imaginatively portrayed through fictional characters and in what ways those characters respond to racism and imposed shame. Based on the theories of trauma, I view African American history as a prolonged history of trauma which haunts generations of blacks. The impact of the past is always present in a variety of ways. Among Morrison¡¦s fiction, I will only choose four of her novels as my major concern to elaborate the fundamental issues that Morrison consistently highlights. The first chapter attempts to investigate aesthetics, ethics and black female subjectivity in Morrison¡¦s The Bluest Eye and Beloved. In the novels, Morrison discloses the racist biases of white aesthetics, as well as its damaging impacts on reshaping the subjectivity of black women. For Morrison, the aesthetic judgment is inseparable from ethics. The second chapter tackles the problematic of racial haunting and the possibilities of working through historical trauma in Beloved. The writing of Beloved not only serves as a reminder as well as a symptom of historical trauma but also offers a way to heal collectively historical trauma. The third chapter is concerned with the issue of postmemory and the crisis of fatherhood in Song of Solomon. The main protagonist, Milkman, still has to work through the multi-ethnic past of his family which, though not directly his, yet haunts him nonetheless. Morrison emphasizes the need for African Americans to forge productive links between past and present. Unless Milkman confronts his past, both personal and collective, he will not know how to appreciate the beauty and power of African-American cultural heritage. The fourth chapter engages with the problematic of black manhood and black nationalism in Paradise. In this chapter, I endeavor to explore how the wounded black manhood is formed in response and in reaction to the historical oppressions of black men as a whole. Set in the sixties and seventies of America, Paradise is a critique to the biased gender politics of black nationalism at that time. It reveals Morrison¡¦s persistent concern with the plight of black men and the continuous victimization of black women.