A method is provided for manufacturing a thin film transistor (TFT) backplate that includes a switch TFT and a drive TFT. The method is conducted such that each of the switch TFT and the drive TFT manufactured therewith includes a source electrode/a drain electrode and a gate electrode, and also includes an etching stopper layer, a semiconductor layer, and gate isolation layer that are disposed between the source electrode/the drain electrode and the gate electrode to form a TFT structure. The gate isolation layers of the switch TFT and drive TFT are formed of different materials, such as SiOx and Al2O3, or SiOx and SiNx, or Al2O3 and a mixture of SiNx and SiOx, such that electrical properties of the switch TFT and the drive TFT are made different.