Abstract：Abstract：A common area of construction berm in subgrade project was considered based on the mechanical stability of slope. When Qinghai—Tibet highway is rebuilt，some sections of the highway construction berm to obstruct seeper in slope angle are adopted；and the berm could be used for heat preservation. Aiming to study the berm¢s effects of ground temperature characteristics of embankment on permafrost，numerical modeling was used to calculate the temperature field，according to the characteristic of the highway，comparative analysis and the research of the laws. It shows that construction berm has limit effect on the ground temperature characteristics of embankment such as artificial permafrost table，annual mean ground temperature and thaw bowl，however，the thaw depth well increase and annual mean ground temperature will rise. High temperature on permafrost berm could deteriorate the degeneration of the frozen soil under the embankment. The result indicates embankment berm on permafrost region should not be regarded as the main measure to improve thermal stability of embankment.
