Heart of Darkness, written by Joseph Conrad, is mainly based on his own experience in Congo, telling the journey of the protagonist Marlow through African jungle to search for an African invader Kurtz. It has always been a controversial work for its ambiguous attitude towards racism and colonialism. In this essay, by analyzing Marlow's attitude towards the Africans and the European colonizer Kurtz as well as the African wilderness, I argue that Conrad, instead of being a "racist", is actually an anti-racist, who means to disclose the atrocity and avarice of the European colonizers and reflect his anti-racism in his writing.