Abstract: Using precision static oxygen bomb combustion calorimeter, the standard energies of combustion of tetraphenylpophyrin, tetra (ρ-methylphenyl)-porphyrin, tetra(ρ-methoxyphenyl) porphyrin, and tetra(o-aminophenyl)-porphyrin at 298.15 K were determined to be -36.1279±0.0103, -36.9368±0.0120, -32.8427±0.0104, and -33.5453±0.0240 kJg~(-1), respectively. The corresponding standard enthalpies of formation at 298.15 K were calculated to be 621.3±8.5, 478.6±10.3, -171.1±9.7, and 474.2±17.2 kJ mol~(-1). The uncertainties of the results were given twice the final overall standard deviation of mean.