A transflective color filter substrate is provided. The transflective color filter substrate comprises a transmissive color filter portion and a reflective color filter portion in one dot region. An area of the color filter colored portion is set to be less than the area of one dot region in the transflective color filter substrate, and an uncolored reflection region, which is capable of reflecting an uncolored light of high brightness without being influenced by the color filter, is formed by a partition layer. Since the pigment density of the coloring layer is set such that the transmitted light has the optimum chroma in the transmissive display mode, it is possible to obtain a displayed image having sufficient chroma in the transmissive display mode. Furthermore, in the reflective display mode, it is possible to obtain a displayed image having sufficient brightness from the colored light, which is reflected from the coloring layer, and from the bright uncolored light, which is reflected from the uncolored reflection region. As a result, it is possible to realize a transflective electro-optical device which has an excellent display quality in both the transmissive display mode and the reflective display mode.