A picosecond laser photolysis system has been constructed for easy measurements of reliable fluorescence decay curves and transient absorption spectra. Luminescent behavior is monitored by a streak camera-SIT camera combination, and the data obtained by calibrating the spatial sensitivity of both cameras and by correcting a deviation from the linearity of time-axis are averaged. Transient absorption spectra are obtained by using a multi-channel photodiode array. Laser oscillation, examination of excitation pulse and analyzing beam, and data processing are controlled by a microcomputer. A program for these operations is developed. Intramolecular excimer formation of dilute polymer solutions, photoinduced charge transfer of tetraphenylporphyrin systems, and two-photon photolysis of neat benzene were studied by the present system.