Objective To observe the effects of curcumin pretreatment on myocardial oxidative stress and apoptosis in heatstroke rats in a dry heat environment and its possible mechanism. Methods Fifty male Sprague-Dawley rats were randomly divided into five groups (n =10): normal control group (NC), dry and control group (DHC), and 50 mg/ kg curcumin (L-cur), 100 mg/ kg curcumin (M-cur), and 200 mg/ kg curcumin (H-cur) pretreatment groups. NC and DHC groups were gavaged with saline, and curcumin pretreatment groups were gavaged with the various concentrations of curcumin once daily for 7 days. On day 8, except in the NC group, the rats were transferred to a climate cabin (Simulated Climate Cabin for Special Environment of Northwest of China) under the conditions of 40. 5 ± 0. 5°C and 10 ± 1% relative humidity for 150 min to establish the heatstroke model of a dry heat environment. Then, the rats were anaesthetized and sacrificed at 150 min, and blood and heart tissues were collected. Serum myocardial enzyme creatine kinase (CK) and lactate dehydrogenase (LDH) were detected by an automatic biochemical detector. Myocardial cell apoptosis was detected by TUNEL method, and the apoptosis index was calculated. Myocardial superoxide dismutase (SOD) and malonaldehyde (MAD) were detected with SOD and MDA kits, respectively. Results Serum CK, LDH,cardiomyocyte apoptosis index, and MDA were significantly higher in the DHC group than in the NC group ( P < 0. 01).CK, LDH, cardiomyocyte apoptosis index, and MDA of curcumin pretreatment groups were decreased with the increase in curcumin concentration, and there was a significant different among the curcumin pretreatment groups ( P < 0. 01).However, SOD showed an opposite trend to MDA. Correlation analysis indicated a positive correlation between the myocardial apoptosis index and serum CK and LDH in rats (r = 0. 302, r = 0. 304, P < 0. 05). There was a positive correlation between the myocardial apoptosis index and MDA (r = 0. 916, P < 0. 01). However, there was a negative correlation with SOD (r = - 0. 863, P < 0. 01). Conclusions Curcumin pretreatment has a protective effect on myocardial injury in heatstroke rats caused by a dry heat environment, which may be mediated through inhibition of oxidative stress and reducing apoptosis in cardiomyocytes.