Abstract: The MoSe2 nanoflakes were synthesized by solid-state reaction method and characterized by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The tribological properties of the 150bn lubricating oil added with MoSe2 nanoflakes were investigated throngh friction testing. The results indicate that the MoSe2 with length of 100-500 nm and thickness of 10-50 nm had nanoflake structure. The friction coeficient of the basic oil containing MoSe2 nanoflakes was higher than that of the basic oil containing MoS2 nanoflakes, The tribological properties of the basic oil containing MoSe2 nanoflakes were the best when the MoSe2 nanoflake concentration was 5wt%.