The feasibility of using the spherical wave method (SWM) to analysis the shaped beam, singly curved reflector antennas is investigated in this paper. It is shown that for low sidelobe level (SLL) beams, or main beam scanned, the reflector length is longer than the line source length, but the cylindrical wave method (CWM) couldn't deal with this additional part. Calculated results by the SWM and the CWM in particular cases are compared. Some calculated results for low SLL and main beam scanned by means of SWM are given.