With the accelerated process of globalization,we are able to access to the wide variety of cultural forms from all over the world conveniently.The United States,a typical country of immigrants,enjoys the world’s first place of ethnic cultural melting.In this paper,the writer takes popular sitcom,The Big Bang Theory,for example to explore the humorous culture of the United States as well as its sources and characteristics from the perspective of subtitle translation. With the accelerated process of globalization, we are able to access to the wide variety of cultural forms from all over the world conveniently. United States, a typical country of immigrants, enjoys the world’s first place of ethnic cultural melting. In this paper, the writer takes popular sitcom, The Big Bang Theory, for example to explore the humorous culture of the United States as well as its sources and characteristics from the perspective of subtitle translation.