Studied 100-atm O2-annealed RuSr2Gd1.5Ce0.5Cu2O10-δ (Ru-1222) compound crystallized in a tetragonal I4/mmm space group crystal structure. Thermo-gravimetric (TG) analysis was successfully applied to establish the oxygen content of the sample studied at 9.63 per formula unit. The DC magnetization data (M vs. T) revealed magnetic transition at ∼100 K followed by superconducting transition at ∼40 K. Low field (-100≤H≤100 Oe) M vs. H hysteresis loop showed a lower critical field (Hc1) value of around 25 Oe. Ferromagnetic component is evidenced at 5, 10, 20 and 40 K. Near saturation field of above 5 T is observed at 5 K. Zero-field returning moment (Mr) and zero-moment coercive field (Hc) values at 5 K are 0.35 μB and 250 Oe. The resistance vs. temperature (R vs. T) behaviour of the sample confirmed superconductivity at around 43 K. Superconductivity transition (Tc) is broadened under magnetic field with strong granularity like steps.