The structure of multilayer Langmuir-Blodgett (LB) films made of a protein (bovine serum albumine)-coproporphyrin(III) conjugate was investigated by means of a fluorescence microscope coupled with the time-correlated single-photon counting registration system. The map of coproporphyrin fluorescence from the surface of protein LB films was measured with picosecond time resolution and spatial resolution of 15 mu m The sample area of 225 x 225 mu m was irradiated step-by-step by a focused beam of a Nd:YAG laser with the accumulation time of 3 s per point. Two different kinds of samples with a regular and irregular distribution of fluorescent labels over the sample were observed. It is worthwhile to note that the fluorescence level of the studied samples is close to the limit of sensitivity of the fluorescence microscope. Another method to optically investigate the structure of the protein LB films is laser interferometry with consequent computer processing of images.