Alpinia oxyphylla is a traditional Chinese medicinal plant, with a medicinal history of more than 1,700 years. Ring leaf blight (RLB) disease, caused by pestalotioid species, is an important disease of A. oxyphylla, seriously affecting the yield and quality of fruits. The causal agent of RLB disease has not been systematically identified and characterized so far. In this study, thirty-six pestalotioid strains were isolated from the leaves and stems of A. oxyphylla collected from 6 cities of Hainan province, China. Based on multi-locus phylogeny (ITS, tef-1α and tub2) and morphological characteristics analyses, seventeen species belonging to three genera (Neopestalotiopsis, Pestalotiopsis and Pseudopestalotiopsis) were identified and six new species (N. baotingensis, N. oblatespora, N. olivaceous, N. oxyphylla, N. wuzhishanensis and N. yongxunensis) were described. Pathogenicity tests revealed that strains of Neopestalotiopsis species caused more severe ring leaf blight on A. oxyphylla than strains of Pestalotiopsis and Pseudopestalotiopsis under wounded inoculation conditions.