The process of the structure restoration of GaAs implanted with Ar+ions at the ion current densities of 10 and 25 μA/cm2and in the fluence interval of 6 × 1013–1 × 1016cm−2has been analysed on the basis of Raman scattering (RS) and Rutherford backscattering (RBS) data taken into account the target heating during the irradiation. The current dependence of threshold fluences which the recrystallization begin at is explained in assumption that the structure restoration is caused of by the mobile monovacancies interaction with the stable vacancy cluster. The existence of the critical ion fluence corresponded to the most perfect GaAs structure has been shown.