Abstract: 【Objective】To identify the influencing factors and obstacle elements to land ecological security in the Heilongjiang reclamation region,in order to provide guidance on how to preserve land ecological security and food security in the area.【Methods】Social,economic,demographic,and other statistical data were collected from 9 sub bureaus in the Heilongjiang reclamation area in 2003,2008,2013,and 2018. 15 indicators were selected using the PSR model to build the land ecological security evaluation system,and evaluate the land ecological security of the Heilongjiang reclamation area on a time and space scale with grey correlation degree,multiplication model,and factor obstacle degree model.【Results】From 2003 to 2018,the land ecological security level in the Heilongjiang reclamation area generally increased. Among the 9 bureaus in the reclamation area,the land ecological security level of Jiansanjiang Bureau continued to rise,the Nine-three Bureau continued to decline,and the other 7 bureaus showed an alternating increase and decrease wave pattern. Grey correlation analysis revealed that the per capita disposable income of farm workers,the level of agricultural mechanization,per capita GDP,population density,and the effective irrigation area of cultivated land were the primary influencing variables of land ecological security in the reclamation area from 2003 to 2018. Factors obstacle degree model analysis demonstrated that the application amount of chemical fertilizer and pesticide,per capita GDP,population density,and per capita disposable income of farm workers were the primary obstacle elements to land ecological security in the reclamation area from 2003 to 2018.【Conclusion】The general land ecological security condition in the Heilongjiang reclamation area has improved,however the land strain has not been lifted completely. To ensure land ecological security,measures such as minimizing pesticide and chemical fertilizer use and managing population density should be taken.

Key words: Pressure-state-response model, Heilongjiang reclamation area, Land ecological security, Grey correlation, Factor obstacle degree model