Abstract: With the rapid development of economic banking in Western Europe and the theoretical background of the rise of the
British bourgeois school of money and finance, Das Kapital discusses the economic phenomenon of interest, probes into the origin and
generation of interest, uncovers the exploitative nature behind interest, and analyzes the factors affecting interest based on the operating
mechanism of interest. On the basis of analyzing the relationship between loan capital and industrial capital, it expands the dialectical
understanding of the production of surplus value. The credit system and virtual capital are the inevitable products of the history of
capitalist interest-bearing capital. Although they seem to be more detached from the relationship with labor surplus on the surface, in
essence, they still cannot change the exploitative nature of the capitalist mode of production. The kernel and extension of the idea of
interest in Das Kapital constitute an important theoretical basis for examining contemporary financial capitalism.

Key words: interest, surplus value, credit, virtual capital