The effect of irradiation mode on blistering of vanadium has been studied using monoenergetic 300 and 400 keV 40Ar+ ions, and with multiple energy 40Ar+ ions with the energy range of 100 and 400 keV (Type I and II). Critical dose for blistering has decreased with increasing annealing temperature for monoenergy and multiple energy Ar implantations, but has been somewhat higher for the latter than the former cases. General features in blisters, flakes and holes formed during subsequent annealing at high temperatures have been rather similar to each other for mono- and multiple energy cases. These features are also similar to those observed on vanadium surfaces after 40 keV He ion implantation with and without subsequent annealing. The effect of irradiation mode on blister formation has been discussed in terms of calculated concentration distribution of Ar atoms taking into account the sputtering effect and in terms of calculated damage energy distribution. Bombarding of the first wall by helium atoms with energy spectrum would modify the aspect of formation of blisters, flakes and holes. © 1979.