Abstract: The project of sloping land conversion program(SLCP) rapidly changing land use structure and improving the level of regional ecological security is the largest investment in ecological construction by far. Mudanjiang Prefecture,Heilongjiang Province,China is a typical cold mountainous region in China,and the ecological system is rather vulnerabile and sensitive. In recent years,the blind deforestation in pursuing short-term interests has resulted in a sharp decrease of forest resources;coupled with the complexity of the terrain,rainfall concentrated, frozen for a long period,the regional soil and water loss is very serious,ecological environment continues to deteriorate. Above all,the paper analyzed the effect of SLCP on the land use structure in Mudanjiang area by using GIS and data statistical analysis technique. By constructing regional ecological security assessment index system and the standard values of indicators for determination and ecological security evaluation model,this paper further analyzed the ecological security of Mudanjiang during SLCP. The results show that:throughout the study period,the unreasonable cultivated land area significantly reduced,and the forest area increased significantly,the woodland area accounted for 72.91% of the total area of the study area by the end of 2013,the effect of SLCP was significant;since the implementation of SLCP in Mudanjiang area in 2000,the ecological situation presented "first improvement after deterioration",but the overall ecological level has been greatly improved over the previous implementation of the project;the implementation of government policies and the intensity of supervision will directly influence the effect of SLCP. The results will help to deepen the understanding of SLCP and the combination of land use change and ecological security evaluation,as well as to deepen the theoretical depth and practical significance of the study.

Key words: ecological security, LUCC, cold mountain