The effective trappingforce is defined and the effective force of a ring beam trap is calculated in the rayoptics regime. A comparison of the effective trapping forces is also given using solidbeam and ring beam. It is shown that the ring-beam gradient laser trap has a highereffective trapping force than the solid-beam laser trap and the stability of the ring-beamlaser trap is improved greatly too. Also the thermal damage of the ring-beam laser trap isreduced.