To strengthen the scientific ecosystem management in the forest-grass ecotone and to further promote forest and grass resources protection and rational utilization, there is an urgent need to ascertain landscape baseline and its spatio-temporal evolution trend. In this study, the forest-grass ecotone of Daxinganling in the Inner Mongonia was chosen as the research area. Based on the Landsat 5 TM images acquired in 2000, 2010 and Landsat 8 OLI images acquired in 2018, the object-oriented decision tree classification algorithm was applied to create the land use datasets first. Next, the dynamic characteristics of land use and landscape pattern evolution were analyzed, followed by a simulation analysis based on the State and Transition Simulation Model (STSM) to project the current land use trend of the study area to 2025. The results showed that:(1) in 2010, the area proportion of forest, grassland, cropland, wetland, urban, saline-alkali lands and desert, and burned area was at 46.93%, 31.66%, 5.02%, 13.73%, 1.08%, 1.55%, and 0.04%, respectively. In 2018, it was at 46.89%, 31.69%, 4.99%, 13.72%, 1.15%, 1.54% and 0.02%, respectively. (2) At the landscape scale, during the period of 2010-2018, the forest dropped by 43.55 km² and its fragmentation severity increased, accompanied by a decreased integrity of forest landscape and a more complex composition of forest landscape, while grassland increased by 38.11 km² and its integrity of landscape improved. (3) Following the current trend, the projected area of forest, grassland, urban and burned area in 2025 from STSM would increase by 92.27, 183.21, 66.2 km² and 10.25 km², respectively, while cropland, wetland, saline-alkali lands and desert would decrease by 184.2, 2.89 km² and 164.84 km², respectively. In the study of large-scale land cover prediction with historical data, the prediction accuracy of STSM model was better than that of Ca-Markov model. Frequent occurrence of forest fire was primarily responsible for the reduction of forest area in the study area. The simulated increase in burned area informed the forest management department of strictly controlling fire risk in the forested area and escalating the capability construction of fire suppression. And the implementation of Natural Forest Protection Project and the Grain for Green Project in the later period was the leading trigger for the improvement of ecological environment. When developing a regional development strategy, the competition between the agricultural production and urban sprawl must be compromised to satisfy the basic requirement of the regional red line for arable lands.