The Rutherford backscattering/channeling technique has been used to investigate the dependence of damage accumulation in GaAs implanted with 1MeV St+ at elevated temperature on the ion dose.Three different dose regions are observed. In the lower dose region from 5×1014 to 2×1015 ions/cm2

the accumulated damage is light and almost independent of the ion dose.In the intermediate region from 2×1015 to 1×1016 ions/cm2

a buried damaged layer under a lightly damaged surface is formed

and the damage accumulation increases rapidly with increasing dose.For the dose region higher than 1×1016 ions/cm2

the damage accumulation has a weak dependence on the ion dose.The related processes are briefly discussed according to the cascade collision and vacancy diffusion.