Objective To observe the effects of curcumin pretreatment on renal pathological changes and the level of oxidative stress in rats with various degrees of heat stroke. Methods Eighty male healthy SD rats were randomly divided into two groups (n =40): saline control and curcumin pretreatment groups. Each group was divided into four subgroups (n=10): 0 min (normal temperature), 50 min, 100 min, and 150 min groups in dry heat environment. Rats of the saline group were administered 0. 9% normal saline, and the curcumin group was administered 200 mg/ kg curcumin. The rats were treated continuously for 7 days. Rats of the 0 min group were subjected to room temperature, while the other groups were transferred to a climate cabin (The Simulated Climate Cabin for Special Environment of Northwest of China) under the conditions of 40. 5 ±0. 5°C and 10 ±1% relative humidity to establish the rat heat stroke model by a dry heat environment.The rats were anesthetized at the corresponding time points, and blood and kidney tissue were collected. The contents of creatinine and urea nitrogen in serum and superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA)activities in homogenates of kidney tissue were detected. Renal tissue was stained with HE, and pathological changes were observed. Results Pathological changes of renal tissue were aggravated by prolonged exposure to the dry heat environment. Pathological renal injury scores were higher in the saline group compared with curcumin pretreatment groups at the same time points ( P <0. 05, P <0. 01). The contents of serum creatinine, urea, and MDA were decreased in the curcumin groups compared with the saline group at the three heatstroke periods ( P <0. 05). The activities of renal tissue antioxidant enzymes SOD and CAT were increased in the curcumin group compared with the saline group ( P < 0. 05). Correlation analysis indicated that renal injury scores were correlated with MDA (r = 0. 75, P < 0. 01). Conclusions Curcumin pretreatment has a protective effect on rat renal injury induced by various degrees of heat stroke in a dry heat environment, and its mechanism may be mediated partly by antioxidant effects.