Abstract: Parabolic equation(PE) is widely used in the numerical simulation of electromagnetic transmission. For the initial fields calculation, PE uses a fixed Gaussian antenna pattern. It does not match the actual antenna pattern and will produce calculation errors. For this deficiency, a method that combines the FEKO and PE is presented to calculate the groundwave of the half rhombic antenna. FEKO was used to calculate the near field distribution which can be used as initial fields of the PE. Compared with the other algorithm about the same kind of problem, although the accuracy of the new algorithm is little lower, but computing speed is sufficient higher, so the new algorithm is quite useful for the engineering.