Hysteresis and threshold switching characteristics were investigated in the indium-gallium-zincoxide (IGZO) thin-film-transistors (TFTs) with inserted Pt-Fe2O3 core shell nanocrystals (NCs) layer between source/drain and IGZO channel. The output curves showed the hysteresis with threshold drain voltage and the transfer curves showed the hysteresis with the shift of threshold gate voltage. These hysteresis, threshold switching, and shift of threshold voltage in both output and transfer curves are caused by charging of inserted NCs. These unique features demonstrated the memory and on/off switching operation by controlling both threshold gate and drain voltages through charging NCs.