Horqin Sandy Land, as the transition zone from the Mongolian Plateau to the Northeast Plain, is located at the intersection of Mongolian, North China and Xing'an flora, with rich biodiversity. It is a typical agriculture-pastoral ecotone and an important ecological barrier in the Northeast Plain. Due to the influence of human factors such as urbanization expansion, grassland reclamation and overgrazing, the Horqin Sandy Land has faced with seriously ecological degradation and ecosystem servicesdecline since the founding of China.Therefore,using remote sensing and geographic information data,a scientific evaluationwas conducted to researchthe implementation process and restoration effect of major ecological restoration projects in last 30 yearsin the area, which had important theoretical and practical significance.Based on the evaluation method in Technical Criterion for Eco-environment Status Evaluation (HJ/T192-2015), the changes of ecological environment of Horqin Sandy Landwere evaluatedin 1990, 2000, 2010 2015and 2020. The results showed that ecological environment index was75.19, 70.20, 73.51, 74.27,and 74.7in 1990, 2000, 2010, 2015, and 2020, respectively. Eco-environmental changes of Horqin Sandy Landcan be divided into three stages:the degradation period during 1990-2000, the recovery period during 2000-2010, and the stable period during 2010-2020. Since 2000, several national ecological projects havebeen implementedinthe region. Consequently, although theEI decreased 4.99 from 1990 to 2000, it increased 4.5from 2000 to 2020. The changes of the EI indicated that the ecological environment protection projects of Horqin Sandy Land had achieved remarkable efficiency. Acceleration of urbanization and shortage of water resources were main restraining factors for the improvement of ecological environment in Horqin Sandy Land. Thus, it is necessary to carry out further ecological conservation projects and groundwater resources utilization engineering.This study could provide scientific basis and practical reference for ecological protection and restoration forHorqin Sandy Land.