Thermogravimetric analysis (TGA) was extended to the measurements of vaporization kinetics and vapor pressures for three oil samples. The energies of activation for the vaporization process and the enthalpies of vaporization were obtained through the vaporization rates and the vapor pressure data. The experimental data from TGA and comparative ebulliometry are distributed in the same linear trends and are in reasonable agreement. The TGA method is a rapid and practical one for constructing vapor pressure curves, especially at low pressure range, for petroleum fractions. Combination of the TGA and the embulliometry, the vapor pressures in a wide temperature range can be obtained.