The photochemical solar cells were prepared by mimicing photoelectrical conversion of photosynthesis using nanocrystalline mesoporous TiO₂ film electrode,which were sensitized by single dye of chlorophyll and xanthophyll and the mixture of different concentration of them. The results of output properties test showed that photoelectric conversion efficiency(η) of the cell sensitized by mixture of chlorophyll and xanthophyll were 5.8 times and 1.4 times as high as of which the cells sensitized by each single dye,the maximum output power(W_opt) was 5.7 times and 1.4 times of the cells sensitized by each single dye. The η and maximum W_opt exceeded linear superposition of the cells were sensitized by each single dye. This synergistic effect would be very important to improve η of the cells and obtain cheap and clean energy with great efficiency.