Disclosed is a photosensitive resin composition for an organic insulating layer. More specifically, the photosensitive resin composition is suitable for forming a substrate of a transflective thin film transistor liquid crystal display (TFT-LCD) or a pattern of an interlayer insulating layer by improving remarkably a pattern property with a high taper angle besides improvement of flatness, sensitivity, heat resistance, and transparency. Particularly, the photosensitive resin composition can provide low power dissipation besides a wide viewing angle and high visibility when being applied to a transflective type display. In addition, the photosensitive resin composition can provide a clear screen under natural light without a backlight by maintaining the brightness of a screen and prominent field visibility.