With global warming, permafrost is subsequently sensitive to human activity, resulting in permafrost degradation. Environmental and ecological problems, as well as thermal stability of engineering, will follow. A geotechnical and geophysical investigation, including ground penetrating radar (GPR) profiling, ground temperature monitoring and drilling, was carried out to study the distribution and characteristics of permafrost in Mohe County of Heilongjiang Province. It is found that GPR could accurately distinguish the distributional range of permafrost, the type of frozen soil and stratum structures. It is revealed that the optimal average radar wave velocity in the layers of study regions (0~10 m) was 0.07~0.08 m?ns~(-1). The effect of artificial disturbance on permafrost in urban areas is stronger than that in rural areas. Permafrost degradation in urban areas is serious, where permafrost table is usually more than 10 m in depth, but it is smaller in rural areas. However, with the increase of population and expansion of city zone, there are many buildings planned to construct or being constructed on swamp grounds surround the city. It is necessary to further study the heating range and thawing depth within permafrost.