The species of Tubakia (Tubakiaceae, Diaporthales, Sordariomycetes) have often been reported as endophytes and pathogens on woody plants. During the investigation of Tubakia species from Fagaceae trees in China, 46 isolates were obtained from diseased leaves and seeds. The characterization of these isolates was based on the observation of morphological characters, the effect of temperature on mycelial growth rate, as well as the combined genes of ITS, tef1 and tub2. As a result, six species were identified: Tubakia americana, T. cyclobalanopsidis sp. nov., T. dryinoides, T. koreana, T. paradryinoides and T. quercicola sp. nov. Among these, T. koreana and T. paradryinoides were firstly discovered in China. Pathogenicity tests were conducted using the conidial suspension on young, excised leaves for these six species, which showed that they were mildly pathogenic to four Fagacece hosts: C. mollissima, Q. acutissima, Q. aliena var. acutiserrata and Q. variabilis.