Based on the principle of the sum of inductive polarity vectors proposed by us, we have designed a new method containing an energy term associated with the sum of inductive polarity vectors for the calculations of the standard enthalpies of formation. Compared with other methods, the new method has a higher calculation accuracy, it contains less calculation parameters, every term has a definite physical meaning. It can also be extended to calculate theoretically the standard enthalpies of fomation of alkane derivatives with some hetero atoms on a carbon atom.