An electromagnetic properties in BiSrCaCuO superconductor were studied. In the measurement of current-voltage properties, the voltage was measured when applying an external magnetic field. The voltage continues to appear after the removal of the magnetic field. This phenomenon was considered as a nonvolatile magnetic effect. The voltage increased with the applied magnetic flux, but it became constant at about $10^{-2}$T. The appearance of the voltage was ascribed to the trapping of magnetic flux.