Abstract: This study aims to identify endophytic fungi in Chinese fir and screen antifungal strains against Pestalotiopsis microspore,the pathogen responsible for copper blight.Using tissue isolation methods,49 endophytic fungal strains were isolated and purified from healthy Chinese fir.These fungi were identified as 16 known species and one unidentified species based on colony morphology and ITS sequence analysis.Diversity assessment revealed a Shannon index of 2.55 and a Simpson index of 0.94,indicating high species diversity of the endophytic fungi in Chinese Fir.Through dual-culture screening,strain SMZ-e,identified as Trichoderma koningiopsis,exhibited significant inhibitory effects on P.microspore,with an inhibition rate of 86.72%.Microscopic observation showed that the hyphae of SMZ-e were capable of coiling around and penetrating the pathogen’s hyphae,suggesting that SMZ-e exerted its antifungal effect through hyper-parasitism.The study confirms the presence of rich diversity of endophytic fungi in C.lanceolata and provides a theoretical foundation for developing these fungi as biological control agents against copper blight.