Permafrost in northern part of Northeast China developed at high latitudes is very sensitive to climate change. Numerical simulations indicate that air temperature in the permafrost regions of Northeast China will continue to rise in the 21st century. Significant warming leads to degradation of permafrost. Northeast China has been warming since the 1950s. The warming trend of Da and Xiao Xing'anling Mountains is most obvious. Permafrost in the Northeast China presents the trend of regional degeneration from south to north. Permafrost degradation in southern part shows: ( 1) permafrost southern boundary is moving northwards,( 2) the permafrost talik is enlarging,( 3) the permafrost vanish gradually. Permafrost degradation in northern part of Northeast China shows: ( 1) permafrost base is moving upwards,( 2) the thickness of active layer is increasing and the ground temperature is rising. The permafrost degradation leads to the deterioration of ecological environment in the cold regions. As a result,the belt of natural forests,dominated by Larix gmelinii,has shifted northward and wetlands have shrunk extensively,among many others. With rapid retreating and thinning of permafrost,large carbon pools sequestered in permafrost could be released to increase net sources of atmospheric carbon,creating a positive feedback,accelerating warming and influencing the global carbon cycle. Subsequently,permafrost degradation causes difference in thermal stability of permafrost and thus cause damage to engineered infrastructures in the cold regions. In addition,it affects microbes in permafrost,carbon cycle,along with ecology and hydrology in the cold region,etc. ,which are important factors of regional climate change and will be the focus of future research. The long-term fundamental data are the foundation of these research. Therefore,researchers need to further refine the permafrost parameters monitoring network,to clarify the relationships between climate change and permafrost degradation,and for evaluating the environmental effects of permafrost degradation.