Abstract: In view of a large choice of materials for organic solar cells, an automatic test sys- tem with microcomputer has been developed. This system can measure the photoelectric action spectra of short-current and openvoltage, the spectral response of quantum efficien- cy and the widtn of forbidden band, therefore it is convenient for the exploration of the efficient organic photoelectric conversion materials. This system can be used for inor- ganic solar cells as well.