The microstructure evolution and low field magnetic properties i.e. initial magnetic susceptibility, stabilization field and magnetic after-effect as disaccommodation of the amorphous and nanocrystalline Fe 80 Zr 4 Ti 3 B 12 Cu 1 alloy were investigated. The heat treatment of the as-quenched Fe 80 Zr 4 Ti 3 B 12 Cu 1 alloy at 773K for 1h leads to its nanocrystallization. It was stated that initial magnetic susceptibility increases and intensity of disaccommodation decreases with increasing of annealing temperature. The magnetic after-effect of the investigated nanocrystalline samples is connected with relaxation processes that occur in the amorphous matrix.