Organic dyes LEG4/DN-F10 as efficient co-sensitized dye system were introduced in dye- sensitized solar cell. With attribution of broaden spectral absorption, the LEG4/DN-F10 co-sensitized dye system could improve the photovoltaic performance of devices in combination with Co(II/III) electrolyte. The photo-transition energy gap of LEG4/DN-F10 system is 1.81 eV. In the present work, power conversion efficiency (PCE) of 4.47% were achieved for device based on LEG4/DN-F10 with short circuit current density, Jsc of 6.87 mA/cm2, Voc of 0.76 V and FF of 56.78 while PCE of device with single dye are 3.41% for LEG4 dye and 3.76% for DN-F10 dye. The co-sensitization is a simple and effective strategy to improve the photovoltaic performance of the device. Further optimization steps are needed to enhance power conversion efficiency and it is under way