【Objective】 To provide theoretical basis for planting forage oat varieties with high yield and high effi‐ ciency in northern desertification area.【Method】 Ten forage oat varieties were planted in Horqin sandy land, and were treated with film coating at high temperature at booting stage with untreated oats as the control. The fluores‐ cence parameters and chlorophyll SPAD values of the leaves were determined.【Result】 The results showed that un‐ der high temperature stress feeding Oat varieties showed lower SPAD value, variable fluorescence value and poten‐ tial photochemical efficiency than those of control. The temperature tolerance of different forage oat varieties was ana‐ lyzed by membership function,and the order was Monica > Junma > Kona > Baylor > Sweet Yan No. 1 > Yan Wang > Menglong > Mu Wang > Mulus > Gunner.【Conclusion】 Monika, Junma and Kona were selected as high temperature tolerant varieties suitable for planting in this area.