A new entomopathogenic nematode (EPN), described here as Steinernema beddingi n. sp., was recovered from a single soil sample collected from a cabbage field in the suburb of Kunming, Yunnan province, China, during an EPN survey in 2002. DNA sequences of both the D3 domain of 28S and the ITS regions of rDNA showed congruently that S. beddingi n. sp. clustered with S. affine and S. intermedium but was clearly distinguished from both. The new species can be separated from all other described species of Steinernema, including the two most closely related species mentioned above, by morphological characters of various stages of the nematode, including lateral field pattern and tail shape of infective juvenile, the spicule and gubernaculum shape of the first generation male, and the tail morphology of the first generation female. Steinernema beddingi n. sp. can also be separated from S. affine and S. intermedium by cross-breeding tests.