Invasive aspergillosis (IA) is the most severe type of Aspergillus infection. Yunnan has developed agriculture, and the proportion of triazole-resistant A. fumigatus induced by triazole fungicides is much higher than that in other regions of China. Inhalation of triazole-resistant A. fumigatus is one of the main factors inducing IA. We gathered five strains of A. fumigatus from the sputum or bronchoalveolar lavage fluid (BALF) of patients with IA in Yunnan. Subsequent testing showed that all of these strains were resistant to triazoles and harboured mutations in the tandem repeat sequence of the cyp51A promoter region, suggesting that they may be triazole-resistant A. fumigatus present in the environment.