Abstract: This article starts from the contradiction between the two solutions about coefficient of self-inductance in coaxial cable and then introduces the magnetic flux linkage of further analysis.By three examples analyzed the relationship between magnetic flux linkage and magnetic flux,it is shown that magnetic flux linkage and magnetic flux is not only integer relations,but can also be the relationship between the scores of times.So that Ψ in the coefficient of self-inductance L =ΨI is the physical quantity of magnetic field lines in the cross-linked with the current,which should not be used full-called flux or total flux,but rather than the magnetic flux linkage.

Key words: coefficient of self-inductance, magnetic field lines, magnetic flux, magnetic flux linkage