Abstract: The pinewood nematode (PWN) causes pine wilt disease which results in catastrophic economic loss to the forest industry. Many nematophagous organisms have been tested, including nematophagous fungi, for controlling the PWN. In 2006, a rare hyphomycetes fungus (isolate CNU 120806) was isolated from infected nematodes found in pineforest soil in south Korea. This fungus is characterized by its ability to produce two types of conidiogenous cells and conidia. However, only the lunate conidia are adhesive and can attach to the cuticle of PWNs and cause subsequent infection. With the consumption of the dead nematode’s body, E.vermicola gradually grows out from the cadavers and then produces new conidia for the next infection cycle. Based on phenotypic characteristics and molecular phylogenetic analyses, we identified the fungus as E.vermicola, the first recorded endoparasitic fungus of the PWN. Resulting from its high infectivity in vitro E.vermicola shows great promise as a biological control agent for combating the devastating pine wilting. In subsequent studies, our isolate has been described and compared with three other isolates (ATCC 74485, CBS 115803, and CBS 100821)and their detailed morphological and molecular characteristics have been determined as have their infectivity against the PWN.The results show that E.vermicola CBS 115803 kills and colonizes almost all the tested pinewood nematode isolates within 4—5 days, i.e. It is highly infectious which has been attributed to its relatively high proportion of lunate conidia. The factors that influence the infectivity of E.vermicola against the PWN and the interaction between E.vermicola and the nematode were also studied in detail. The results show that the high potential application of certain fungus formulations as a commercial biocontrol agent against the PWN.