Abstract: For the final stage of a launch vehicle which cannot start multiple times, the main constraint of a highly ec-centric orbit launch mission is the argument of perigee, which is conditioned by the range. This paper studies the pay-load capacity at different launch sites for a highly eccentric orbit (e.g. GTO) and gives a method to improve the payload capacity with an argument of perigee constraint by increasing the sliding time before the final ignition and simultaneously adjusting the launch azimuth and yaw at the final stage. An example of launching to GTO orbit on a rocket from Hainan is given, which proves that the method has strong engineering value.