Abstract: Based on the equivalence between momentum representation and coordinate representation, an alternative method is presented,where the momentum representation and the Feynman＇ s path integral are employed to calculate the propagator function of a particle in a constant force field,then the result is transformed into the coordinate representation. We present a way to solve the Feynman＇ s path integral, which exhibits the high value of momentum representation if the solution of one-dimensional motion of a particle in a constant force field.

Key words: momentum representation, constant force field, path integral