Abstract:[Objective] To construct a transformation system in Gliocladium sp.6.102,a Cordyceps-colonizing fungus producing a variety of epipolythiodioxopiperazine (ETP) compounds with drug potentials.[Methods] Agrobacterium tumefaciens-mediated transformation (ATMT) was used to transform Gliocladium sp. 6. 102. The factors of bacterial cell concentration,co-cultivation time,pH and acetosyringone concentration were optimized.[Results]A total of 50-100 transformants per 106 fungal conidia was obtained via the optimal ATMT method.The genes encoding hygromycin B phosphotase and enhanced green fluorescent protein (EGFP) were transferred into Gliocladium sp. by the optimal ATMT method. The marker genes were successfully expressed and stably maintained in the transgenic fungus.[Conclusion]A transformation system was established for Gliocladium sp. 6. 102 and this system may be useful to identify ETP biosynthetic genes in Gliocladium.