An investigation of Trichoderma biodiversity involving a large-scale environmental gradient was conducted to understand the Trichoderma distribution in China. A total of 3,999 isolates were isolated from forestry, grassland, wetland and agriculture ecosystems, and 50 species were identified based on morphological characteristics and sequence analysis of genetic markers. Trichoderma harzianum showed the largest proportion of isolates and the most extensive distribution. Hypocrea semiorbis, T. epimyces, T. konilangbra, T. piluliferum, T. pleurotum, T. pubescens, T. strictipilis, T. hunua, T. oblongisporum and an unidentified species, Trichoderma sp. MA 3642, were first reported in China. Most Trichoderma species were distributed in Jilin and Heilongjiang Provinces in northeast China and the fewest were distributed in Qinghai Province. Based on the division of ecological and geographic factors, forestry ecosystems and low-altitude regions have the greatest species biodiversity of Trichoderma.