Abstract: A liquid crystal projector having increased contrast ratio and color saturation is disclosed. Due to the response of human eyes with respect to green color is much higher than that of each of red and blue colors, when the contrast ratio of green light is increased, the contrast of the system is regarded as been greatly increased. Thereby, the contrast of green light is increased by two PS polarizing beam splitters in this system, so that the contrast ration of the system can be greatly increased. Furthermore, a color selector is also utilized for selectively changing the polarization of a single color, thereby simultaneously increasing the contrasts of three colors of R, G, and B by way of three PS polarizing beam splitters.