An artificial screening technique evaluating freezing tolerance in orchardgrass and meadow fescue was developed for the purpose of breeding winter-hardy cultivars. Four-leaf-stage seedlings were hardened at 3℃ under 8-hr-day length for 14 days, followed by freezing treatment for 16 hr at -8 to -10℃ for orchardgrass and at -12℃ for meadow fescue. Visual scores for freezing damage were recorded 2 and 4 weeks after the treatment. Varietal differences in the freezing tolerance were significant. Scandinavian and Canadian cultivars of meadow fescue showed very high survival rates, which were in good agreement with the results of field trials, Effects of selection for freezing tolerance were clearly recognized among the progenies derived from the surviving seedlings. This technique was employed in the practical breeding program in Japan, under which Wasemidori for orchardgrass and Tomosakae for meadow fescue, both highly tolerant varieties to freezing, were successfully developed. The technique proposed in this paper could be applied to other temperate grasses for artificial selection.