The Topological Inner Structure of Chern--Simons Tensor Current and the World-Sheet of Strings

Using the decomposition theory of U(1) gauge potential and Ф-mapping topological current theory, we investigate the topological inner structure of Chern--Simons tensor current. It is proven that the U(1) Chern--Simons tensor current in four-dimensional manifold is just the topological current of creating the string world-sheets.