Abstract-Based on the vectorial angular spectrum representation and the method of stationary phase, internal vectorial structures of a phase-flipped Gauss (PFG) beam diffracting in the far field are derived in analytical forms. The energy flux for the TE term, TM term and the whole beam are derived and depicted by numerical examples. Influences of the f parameter on the whole energy flux distributions are analyzed. Discrepancies of the whole energy flux distributions between the paraxial and non-paraxial cases are shown in detailed manners. Furthermore, influences of the f parameter on discrepancies between two cases are also studied.