A display drive circuit of the invention has: an initial-color-gamut-apex-coordinate-storing unit capable of storing initial color gamut apex coordinates; a user-target-color-gamut-apex-coordinate-storing unit capable of storing user target color gamut apex coordinates; a saturation-expansion-coefficient-deciding unit for deciding expansion coefficients of saturation data based on the initial and user target color gamut apex coordinates; and an expansion unit for expanding saturations of display data based on the saturation expansion coefficients. The expansion coefficients of saturation data are decided based on the initial and user target color gamut apex coordinates, and saturations of display data are expanded according to the expansion coefficients. Thus, the degree of expanding the saturations can be controlled for each color gamut or each of R, G and B color properties of an LC display panel.