The design idea and the spot experimental scheme of the particle improved roadbed are analysed in detail and deformed law with time of the particle improved roadbed in the cycle of freezing and thawing. The results indicate that the deformation of the particle improved roadbed presents the corresponding frost - heave deformation with the cycle of freezing and thawing. As compared with the ventilated embankment, the particle improved roadbed can, to some extent, shorten the freezing period and ease the frost-heave deformation.