The measurement of characteristics of spectra and time of ultrafast fluorescence is studied by combination of the femtosecond laser pulse and the streak camera with a time resolution better than 2 ps. The generation of fluorescence is analyzed, the way to measure time-resolved fluorescent spectra is proposed. The data of the time-resolved fluorescent spectra and fluorescent life-time of an organic optical disk named the azo dye-doped thin film are given.