Marxism is an important school in the research field of the ethnic-national issues, which differs widely from the Liberal school. Discussing the origin and future of family, clan, tribe, nationality, nation, and state from a materialistic perspective rather than an idealistic one is the epistemological characteristic that marks the Marxists out from the Liberals; and considering the ethnic-national issues under the general issue of proletarian revolution constitutes the characteristic of Marxist theory of practice. Nonetheless, the Marxist ideas about nation, which were not spontaneously shaped, were developed gradually in a context that the European power politics drove a wedge and exaggerated hostility among nationalities, and along with the spreading of the national concept that exposed the conspiracies of the regional hegemonic powers and corrected the wrong ideas. This paper is intended to demonstrate the ideas and viewpoints of Marx and Engels on nation by recalling the spreading process of the national concept from Western Europe to Central and Eastern Europe, as well as the explanations and responses by the founders of Marxism to the ethnic-national issues.