Abstract: The effect of different annealed time on organic solar devices were investigated. Results indicate that the light transmissivity of the P3HT/PCBM active film is improved and the reflectivity deceases in the annealing process. The X-ray diffraction analysis reveals that the degree of crystallite is different in those films by different annealing time. It results in a different quantum efficiency with the different devices. The short-circuit current is 0.75 mA/cm² when the annealing temperature is 140 ℃ for 30 min. The photoelectricity conversion efficiency of the devices is 0.034 64% which is the largest one compared with other devices