Although amorphous alloy ribbons have lower core loss,serious loss deterioration occurs in amorphous cores constructed from amorphous alloy ribbon for distribution transformer.In the present study,the loss deterioration mechanism and influencing factors of amorphous cores for distribution transformers were investigated.The influence of distributed gaps on core loss of transformer core was calculated by simulation software and validated by experiments.The boron fluctuation of amorphous alloy ribbons affects the annealing temperature of amorphous transformer cores.A superior core annealing technique with annealing parameters was developed,and appreciable decrease in core loss was obtained.