Abstract: To understand the response of forage oats（Avena sativa L.） to drought stress and evaluate the drought resistance of the cultivars. In this study, seven forage oat cultivars were subjected to natural drought stress after 15 days of seedling emergence using the water control method, and plant height, leaf length, leaf width, leaf area, leaf number, aboveground biomass and root dry weight were measured at 0 day, 7 days and 14 days of stress, respectively. Principal component analysis, affiliation function method and cluster analysis were used to evaluate the comprehensive drought resistance of the cultivars. The results showed that with the extension of drought stress, the plant height, leaf length and root dry weight of seven cultivars forage oat showed an increasing trend, while leaf width and leaf number showed a decreasing and then increasing trend. The leaf area of cultivar Grain King showed an increasing trend, while the leaf area of cultivar Monida, Guyuan Big Oat, Shepherd King, Xiyue, Danyan 444, and Mulesi showed increasing and then decreasing trend; The aboveground biomass of cultivars Xiyue, Shepherd King, and Guyuan Big Oat showed an increasing and decreasing trend, while the aboveground biomass of cultivars Grain King, Monida, Danyan 444 and Mulesi showed an increasing trend was the same. The drought resistance of cultivars obtained by the three comprehensive evaluation methods, of wthich cultivar ’Grain King’ had strong drought resistance, the cultivar Monida had medium drought resistance, and the cultivars Guyuan Big Oat, Xiyue, Shepherd King, Danyan 444, and Mulesi had weak drought resistance.