When a two-dimensional superconducting mental surface is passed through by two infinite straight magnetic flux，it is shielded by superconductivity.It is supposed that the change rate of flux is not equal to zero at the beginning，which induces two opposite and equal currents on the two - dimensional superconducting mental surface.In this situation，when the change rate of flux is changed to zero and both magnetic fluxes remain constant，a new physical interference effect appears. In this paper， the interference streamline distribution on the two-dimensional superconducting mental surface is calculated and simulated. We named the new interference phenomenon L-J effect considered as a two-dimensional A-B effect.