Due to the increasing impact of global climate change and human activities on ecosystems, land degradation is becoming more serious in arid and semi-arid areas. The United Nations Convention to Combat Desertification (UNCCD) has put forward the goal of land degradation neutrality (LDN) to avoid, reduce and reverse land degradation. In this paper, we introduced the development of the concept and assessment method of LDN. Then, the Mongolian Plateau (MP) was taken as an example to evaluate the performance of the LDN goal using three key indicators: land cover, land productivity and soil organic carbon from 2001 to 2020. The results showed that compared with the ecosystem state in the baseline period (2001-2010), the area of newly restored area (10.83×10⁴km²) in the reporting period (2011-2020) was larger than that of newly degraded area (7.77×10⁴km²), indicating that the LDN goal had been achieved in the Mongolian Plateau in 2020. During the past two decades, the restored area exceeded the degraded area by 6.87×10⁵km² (2001-2010) and 9.44×10⁵km² (2011-2020), respectively. However, there are some problems when using LDN assessment methods, like uncertain data, simple grading, insufficient indicators and lack of quantitative description. Therefore, we propose that future research need to further optimize and develop assessment indicators and methods. In addition, there are relatively few empirical studies based on the LDN conceptual framework up to now. The regional assessments can help to judge the status of regional land degradation and identify critical areas, which lead us to formulate spatially explicit ecological restoration strategies. We conduct this study in a typical area of arid and semi-arid regions, and aim to provide a scientific basis for formulating land management measures and coordinating sustainable development goals in the MP and other arid and semi-arid regions.