This thesis examines unstable cultural identity and how the western culture impacts the local culture in India in the postcolonial era in the novel, The Inheritance of Loss, which is written by Kiran Desai, who sets her novel in India in the postcolonial era when globalization unleash its influence around the world. Thus, in chapter one, this thesis concentrates on the impacts of western culture on the local Indian residents in Kalimpong and the Indians living abroad as illegal immigrants, and investigates the diasporic experiences of two protagonists, the judge and Biju, of two generations both encounter the cultural conflicts and racial discrimination. But their pursuing of wealth and reputation in western countries leads to the loss of their cultural identity. In chapter two, this thesis would like to show the longing for modernity in the postcolonial era and nationalism in India. In Kalimpong, where both the upper class and the lower class immerse in the western culture, neglecting the outside world which has already been in disorder. Although India recovers its political freedom, the social situation in north India is still in the unrest because of the chaotic relations between diverse ethnicities. Desai focuses on the GNLF movement conducted by the Nepalese, who suffer from inequality in India sovereignty. In the last chapter, this thesis explores one female protagonist, Sai. A sixteen-year-old girl, who is a hybridity of both Indian culture and western culture. This young girl does not mind the differences of class and culture, who thus becomes the character with the potential to cross the border between different classes, nations and cultures.