A new technique of investigation of properties of granulated high-T(c) superconducting films has been developed. Irreversible dependence of resistivity upon magnetic field has experimental studied and explained theoretically. Demagnetization fields of separated grains stipulate for hysteresis. The superconducting phase concentration, critical field of the grain, concentration 1.1 x 10(16) cm-3 and mobility 2 x 10(5) cm2/V sec of effective carriers in the normal phase even in cases of the films not showing transport superconducting current have been determined.