vA modified Xα-SCF method is proporsed for calculating atomic structure parameters of a molecule and further characterization or calculation of some other properties of a molecule could be performed based on the calculated parameters. The method could be used to calculate the atomic parameters in different environments. Since the basic parameters as wavefunctions, radial distribution functions and scattering factors were known by the calculation, the method in fact can be extended to the calculation of various atomic structural parameters. In addition, the calculation could be carried out by a micro-computer, it is time-saving, and the calculation results are comparable with those from the ab initio method.