Abstract: A programmable Gamma circuit of a LCD display device includes a control signal generator for generating multiple control signals; one or more voltage-reducing circuits for generating multiple voltage-reduced signals corresponding to a common voltage feedback signal outputted from a LC array of the LCD display device; and multiple amplifying circuits for respectively amplifying the multiple coupled signals to generate multiple Gamma calibration signals. The multiple voltage-reduced signals are respectively coupled with the multiple control signals to generate multiple coupled signals.