Abstract: Well resolved ESR spectra of CuTAPP [Copper tetra-(p-trimethylammoniumphenyl) porphine iodide] supported on active carbon was obtained by proper dilution of CuTAPP on the substrate. The hyperfine lines of copper, super-hyperfine lines of the four nitrogen atoms and anomalous lines appeared on the spectrum. Computer simulated spectrum of CuTAPP was found to be in good accordance with the experimental one. The ESR spectrum of CuTAPP supported on active carbon was discussed in detail to yield the ESR and derived parameters, which are found to be close to those of non-supported copper porphins and phthalocyanins.