[Objective] Few studies have been reported about the biological control of plant parasitic nematodes by Microbacterium maritypicum. The purpose of this study was to determine the nematicidal activity of M. maritypicum Sneb159. In addition, nematicidal active compounds were separated from the culture supernatant of strain Sneb159. The study will provide fundamental knowledge about the development of biological pesticides. [Methods] We evaluated the direct antagonism to the second-stage juveniles (J2s) of Heterodera glycines in vitro. The nematicidal compound was separated and purified from culture supernatant of strain Sneb159 using organic solvent extraction, followed by silica gel chromatography and semi preparative high performance liquid chromatography according to the mortality of J2s. We characterized the compound by nuclear magnetic resonance spectrum. [Results] Strain Sneb159 showed strong nematicidal activity. The mortality of H. glycines J2s in Sneb159 treatment was significantly higher than that in the control after 24 h and 48 h incubation. One active compound, phenylacetamide, was obtained from culture supernatant of strain Sneb159. [Conclusion] To our knowledge, this is the first report to describe the nematicidal activity of M. maritypicum against H. glycines. The results suggested that strain Sneb159 and phenylacetamide have potential applications for biological control of H. glycines.