Abstract: An index system was established by using the economy-environment–society (EES) model, and an evaluation model of land ecological security was established by using the matter element method of entropy weight. The temporal and spatial changes of land ecological security and its influencing factors in the Yimeng Mountain area were studied. The results showed that: (1) From the perspective of time change, the land ecological security in the Yimeng Mountain area in 1995, 2000 and 2005 was at grade IV, and that in 2010 and 2015 was at grade III, showing a gradually improved trend. The number of counties at a high level of land ecological security was increased, while that at a low level of land ecological security was decreased. (2) From the view of spatial change, except for small fluctuations in individual counties, the level of land ecological security in the Yimeng Mountain area showed a gradually improved trend, while the speed of promotion was different among counties, the absolute difference fluctuated upward, and the relative difference fluctuated downward. The spatial distribution of county land ecological security was uneven. The county land ecological security was stronger in the western region than that in the eastern region, and was higher in the southern region than that in the northern region. The improvement speed of land ecological security level in the eastern region was faster than that in the western region. (3) Ten indicators, such as forest coverage, had an important contribution to the improvement of land ecological security level in the Yimeng Mountain. Five indicators, such as natural population growth rate, had little influences on the change of land ecological security level. Five indicators, such as GDP growth rate, were the main factors restricting the improvement of land ecological security level. Combination of the entropy weight method and matter element model showed practical value and operability to evaluate land ecological security.