Abstract: It is a purpose of this invention to accurately measure the properties of petroleum and petroleum fractions from a small volume of sample oil in a short period of time with less cost and energy for the analysis by vaporizing and distilling the respective components contained in the sample to be measured by a distillation apparatus. The components in the sample oil are first separated and vaporized by the distillation apparatus and the boiling point distribution of the respective components is measured. The property estimation means is equipped with a property estimation model for evaluating the property estimate value outputted from the property estimation model. The method is incorporated into standard or otherwise any distillation test apparatus to provide accurate measure of the thermodynamic and transport properties of undefined multicomponent mixtures such as crude oil, petroleum fractions, gas condensates and the like.