To investigate the effects of four natural chrysotile asbestos in major mining areas of China on lung injury and the expression of HO-1 and HSP-70 in lung tissues of Wistar rats, the authors collected samples of four natural chrysotile asbestos from the four mining areas of China. The fiber morphology, surface active group and chemical composition were analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray fluorescence diffraction. Wistar rats were randomly divided into 5 groups (Akesai of Gansu, Mangnai of Qinghai, Xinkang of Sichuan, chrysotile groups and physiological sodium chloride solution negative control group of southern Shaanxi), with the chrysotile groups treated with intratracheal instillation. Six rats were put to death in batches 1 month, 6 months and 12 months later respectively, and lactate dehydrogenase (LDH), alkaline phosphatase (AKP), and total protein (TP) in bronchoalveolar lavage fluid (BALF) were measured. The expression levels of heme oxygenase 1 (HO-1) and heat shock protein 70 (HSP-70) mRNA in lung tissues were detected by qRT-PCR, and the expression levels of HO-1 and HSP-70 protein were detected by western blot. The results showed that the LDH of Gansu Akesai, Qinghai Mangnai and Sichuan Xinkang chrysotile groups and the AKP and TP in each chrysotile group were higher than those in the negative control group at each time point (P<0.05), and increased with the prolonged exposure time (P<0.05). As for HO-1, HSP-70 mRNA and HO-1, HSP-70 protein expression levels, it is shown that, 1 month later, the values of each exposure group was higher than those in the negative control group (P<0.05); 6 months later, values of each exposure group was higher than those in the negative control group, and values of Gansu Akesai and southern Shaanxi chrysotile groups were lower than those in the Qinghai Mangnai and Sichuan Xinkang chrysotile groups (P<0.05); 12 months later, values of Gansu Akesai and Southern Shaanxi chrysotile groups were higher than those in the Qinghai Mangnai and Sichuan Xinkang chrysotile groups, whereas values of Qinghai Mangnai and Sichuan Xinkang chrysotile groups were lower than those in the negative control group (P<0.05).