Abstract: 【Objective】 To study the effects of different potassium application rates on photosynthetic characteristics and yield of peanut under drip irrigation in the hope of providing a basis for peanut planting in Xinjiang. 【Methods】 Huayu 9610 and Heihua 5 were used as experimental materials, and four potassium application treatments were set: 0 kg/hm² (K₀), 150 kg/hm² (K₁), 225 kg/hm² (K₂) and 300 kg/hm² (K₃). The effects of different potassium application rates on photosynthetic parameters, chlorophyll content and fluorescence parameters of peanut were compared, and the effects of different potassium application rates on photosynthetic characteristics and yield of peanut under drip irrigation were explored. 【Results】 The net photosynthetic rate, transpiration rate and stomatal conductance of Huayu 9610 and Heihua 5 were significantly increased under K₂ application, and the intercellular CO₂ concentration was decreased. Compared with K₀, they were increased by 9.67%, 60.49% and 13.53%, 14.25%, 55.97% and 15.14%, respectively. The chlorophyll content in leaves reached the peak of 2.92 mg/g and 3.01 mg/g on the 80th days after emergence, respectively. During the whole growth period, ETR, PSⅡ maximum photochemical efficiency (F_v/F_m) and PSⅡ potential photochemical activity (F_v/F_o) of Huayu 9610 and Heihua 5 reached the maximum values of 98.34,0.84 and 4.24,98.57,0.85 and 4.32 at 80 d K₂, respectively, which were significantly higher than those of K₀. The number of pods per plant, 100-pod weight, 100-kernel weight and kernel rate of Huayu 9610 and Heihua 5 were higher than those without potassium fertilizer. The yield difference of different potassium treatments was K₂>K₃>K₁>K₀. In the experiment, the highest yield of Huayu 9,610 and Heihua 5 was 9,428.71 kg/hm² and 9,968.35 kg/hm², respectively, which was 33.66 % and 35.26% higher than those without fertilizer. 【Conclusion】 The chlorophyll a/b, photosynthetic rate, stomatal conductance, transpiration rate, electron transport rate (ETR), maximum photochemical efficiency of PSⅡ (F_v/F_m) and potential photochemical activity of PSⅡ (F_v/F_o) of functional leaves of Yuhuayu 9610 and Heihua 5 on the 80 th days after emergence reach the maximum under K₂ application rate. The yields of different potassium treatments are T₂K₂>T₁K₂>T₂K₃>T₁K₃>T₂K₁> T₁K₁>T₂K₀>T₁K₀. The yield of Huayu 9610 and Heihua 5 reach the highest under K₂ treatment, reaching 9,428 kg/hm² and 9,968 kg/hm², respectively. The yield of Heihua 5 is higher than that of Huayu 9610, indicating that the increase of potassium fertilizer in Xinjiang has obvious effect on peanut yield.