To select suitable high-quality oat varieties for cultivation in the Qinghai Lake area， ten introduced oat （Avena sativa L.） varieties were evaluated for yield and related traits， and the structural equation modeling was employed to analyze the key factors that affecting yield. The results showed that ‘Model’ and ‘Esker’ had relatively short growth periods （132 and 125 days， respectively）. ‘Monida’ exhibited superior plant height （61.93 cm） and hay yield （12 672.60 kg·hm^-2）. ‘Baler 2’ and ‘Haymaker’ performed better in leaf area and leaf perimeter. ‘Everleaf’ had the highest leaf area index （5.29） and， together with ‘Forage’， produced more spikelet whorls （6.22）. ‘Model’ had the highest thousand-grain weight （42.68 g）. And ‘Haymaker’ achieved the highest seed yield （9963.06 kg·hm^-2）. Random forest analysis indicated that the leaf area and grain weight per spike had significant effects on seed yield， while structural equation modeling revealed that yield was jointly regulated by both the direct effects of variety and the indirect effects mediated through the leaf area index. Overall evaluation suggested that ‘Haymaker’ had remarkable advantages and could be recommended as the dominant oat variety for the Qinghai Lake area.

Qinghai Lake area  /  Oat varieties  /  Hay yield  /  Seed yield