AbstractThe essential oil of Mentha canadensisaerial parts was obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromaotography-mas spectrometry (GC-MS). A total of 36 components of the essential oil were identified. The major constituents in the essential oil of M. canadensiswere menthol (28.8 %), α-pinene (16.4 %), menthone (12.7 %), α-terpineol (6.3 %) and limonene (5.5 %). Four active constituents (limonene, menthol, α-pinene and α-terpinol) were isolated from the essential oil of M. canadensisbased on bioactivity-directed fractionation. The essential oil of M. canadensisaerial parts exhibited nematicidal activity against cereal cyst nematodes (Heterodera avenae) and root-knot nematodes (Meloidogyne incognita) with LC values of 385.7 μg/ml and 139.0 μg/ml, respectively. The isolated constituents, menthol and α-terpinol possessed nematicidal activity against H. avenaeand M. incognitawith LC50values of 242.5 μg/ml, 190.3 μg/ml and 147.4 μg/ml, 115.2 μg/ml, respectively. The study indicated that the essential oil of M. canadensisaerial parts and its two major constituents, α-terpineol and menthol have a potential to be developed to a natural nematicides for the control of nematodes.