Abstract: The interactions between a fluorescent molecule,5, 10, 15, 20-tetra（4-hydroxyphenyl） porphyrin P<SUB<0</SUB<, and Triton X-100 micelle are investigated by UV-vis absorption and fluorescence spectra. The results show that the deprotonation of P<SUB<0</SUB< has occured in micelk solutions in the basic titration process. By means of analyzing the relationship between the solubilizing location of the porphyrin in TX-100 micelle and the microenvironment polarity, it is shown that P<SUB<0</SUB< is involved in a transfer process from the inner to the outer surface of TX-100 micelle as the hydrophilic ability is increased. At the same time, the reasons of fluorescence quenching effect are explained primarily.