The ability of limiting powerful laser radiation (up to 400 MW/cm2) by solutions of tetraphenylporphyrin (TPP) and its derivatives, as well as spectral-luminescent and photochemical properties of these molecules at their excitation to different electronic states by radiation of different wavelength and intensity is investigated. The quantum yields of fluorescence from S1 and Sn excited states and, in some cases, the quantum yields and features of phototransformations under exposure to powerful laser radiation have been determined.