Abstract: The evaluation of land ecological security is one of the basic works for ecological civilization construction.It helps maintain the regional ecological security and sustainable development of social economy and thus has been attracted wide attention in recent years.Taking Jiangjin District,Chongqing as the study area,this paper evaluated its land ecological security based on the entropy weighted matter-element model.The results showed that the land ecological security in Jiangjin District in 2011 and 2012 was "critical secure" and it became "secure" during the time period from 2013 to 2015.The overall land ecological security has been improving in the district and it is changing towards "securer".However there is a significant spatial difference of land ecological security in Jiangjin District with its north-east area better than the other parts,and its south and middle area,the worst.The rural per capita net income,the proportion of ecological infrastructure land,the proportion of regional development coefficient and the arable land per capita were the main factors of the land ecological security in Jiangjin District.It was suggested in this paper for the local government to keep executing the ecology first policy in the regions with high ecological security and to conduct the rectification and reforming measurements to improve the ecological security in those regions where the security level needs to be enhanced.

Key words: land use, eco-security, entropy weighted matter-element model, Jiangjin District